UK Weight Loss Statistics Report

Obesity poses a potentially significant public health challenge in the UK, with more than a quarter (26%) of adults considered obese and almost two-fifths (38%) classed as overweight.

Recent developments in weight loss interventions, such as pharmacological treatments and surgery, alongside more traditional methods of adopting a healthier lifestyle, are helping to transform the healthcare landscape and present new opportunities.

Our weight loss experts have compiled the latest report for 2025 to show how average weight loss statistics and trends across the UK are changing. This includes topics such as the most popular ways to lose weight in the face of growing demand for weight loss injections and medications.

Top 10 must-know UK weight loss statistics 2025

Around 1.5 million people in the UK were using weight loss medications as of Q1 2025 (Source: IQVIA)
The UK economy could be boosted by £4.5 billion if everyone eligible were given a weight loss injection (Source: The Guardian)
Just under half of the people surveyed by Ipsos plan to lose weight in 2025 by doing more regular exercise (Source: Ipsos)
As of May 2025, Second Nature was the most commonly searched weight loss programme in the UK, based on Google Trends data (Source: Chemist4U)
On average, patients using Wegovy or Mounjaro lose between 14-20% of their body weight within their first year of treatment (Source: BBC)
As of May 2025, Mounjaro and Zepbound were the most commonly searched weight loss drugs, according to Google Trends (Source: Chemist4U)
On average, the proportion of media articles on different weight loss injections with a positive sentiment is about the same as those with a negative one (41% vs. 42%) (Source: Chemist4U)
The average weight loss for patients using the NHS Digital Weight Management Programme is 3.9kg (8.59lbs) (Source: NHS England)
Almost nine in 10 of those surveyed claim weight loss injections have improved their quality of life (Source: Chemist4U)
Half of those questioned have noticed more respect or attention since taking weight loss injections (Source: Chemist4U)

UK weight loss industry statistics

Integrated weight management centres now offer a holistic approach to obesity treatment, combining medical, surgical, and behavioural interventions. As a result, the UK weight management market is expected to reach £1.5 billion by 2027, with a compound annual growth rate (CAGR) of 9% in the space of three years.

A 2025 study presented at the European Congress on Obesity in Malaga, Spain, concluded that giving weight loss injections to all those eligible could boost the UK economy by £4.5 billion. Coupled with an estimated cost of £100 billion a year in tackling obesity and type 2 diabetes, this would prove a significant economic saving for the UK government and its healthcare costs.

Results from the data revealed that those taking semaglutide were able to work five extra days and carry out 12 days of unpaid work, alongside reducing their consumption.

These productivity gains (i.e., the annual net production value) were calculated at an average of £1,127 per person.

This equated to:

Approximately £4.31 billion in potential net productivity gains for those living with obesity
Around £200 million for those diagnosed with type 2 diabetes [3]

The UK weight loss market experienced an average monthly volume growth of almost a quarter (24.6%) between October 2024 and March 2025. As a result, the estimated number of people across the UK using weight loss medications reached 1.5 million by the end of Q1.

According to IQVIA, the amount that UK adults spent on private access to medicines during this period also grew by more than half (+56%), from £503 million to £784 million. More than a quarter of this spending (26.8%) related specifically to weight management medication.

Of the 1.527 million packs supplied in March 2025 alone, an estimated four-fifths (80%) were from online providers.

Despite this, there was still a £72 million increase in other private treatments once weight loss medications were excluded, representing a rise of just over a sixth (+17%) for the month.

Average weight loss statistics in the UK

What is a healthy rate of weight loss?

If you’re overweight or obese, then losing 5-10% of your body weight can result in multiple benefits, such as improved blood circulation, greater mobility, and a reduction in chronic health conditions later in life.

Examples of healthy weight loss statistics for different body weights

If you weigh…	A 5% weight loss is…	A 10% weight loss is…
70kg (11st)	3.5kg (8lb)	7kg (15lb)
80kg (12st 8lb)	4kg (9lb)	8kg (18lb)
90kg (14st 2lb)	4.5kg (10lb)	9kg (20lb)
100kg (15st 10lb)	5kg (11lb)	10kg (22lb)
110kg (17st 5lb)	5.5kg (12lb)	11kg (24lb)
120kg (18st 13lb)	6kg (13lb)	12kg (26lb)

(Source: Nutrition.org)

According to national guidelines, gradual weight loss is best achieved by cutting down your calorie intake or increasing your activity levels equivalent to 500-600kcal a day. This should lead to an average weight loss per week target of 1-2lbs (0.5-0.9kg). This is usually helpful for the first few months to get you on your weight loss journey.

For most men, this means consuming no more than 1,900 calories a day, compared to 1,400 calories for the majority of women.

As part of this, you should aim to get your ‘5 A Day’, with 80g of fresh, canned, or frozen fruits or vegetables counting as one portion.

Some people opt for a very low-calorie diet (VLCD), which involves consuming less than 800 calories per day. This can lead to rapid weight loss, but NHS advice states that this should usually not be followed for more than 12 weeks at a time.

Did you know?

According to parental opinions on weight loss, more than two in five (42%) of those surveyed by Chemist4U found it hard to ensure their child was eating a balanced diet and a third (33.5%) were concerned about their children being exposed to weight loss advertising.

Reducing your calorie intake may help you lose excess body fat, but maintaining a healthy weight also requires regular physical activity to burn energy. It can also reduce the risk of type 2 diabetes by two-fifths (40%).

The UK’s Chief Medical Officers recommend that adults should do at least 150 minutes of moderate exercise a week, such as five sessions of 30-minute activities. This involves any activity that increases your heart and breathing rate (see table below).

Examples of moderate and vigorous exercise for healthy weight loss

Moderate exercise	Vigorous exercise
Brisk walking	Running
Cycling	Most competitive sports
Recreational swimming	Circuit training
Dancing

(Source: NHS)

An alternative option is to do 75 minutes of vigorous activity a week, or a combination of the two. During vigorous exercise, your heart should beat rapidly, and breathing should be hard so that you cannot hold a conversation (see table above).

Check out our hints and tips for how to stay motivated during your weight loss journey.

Weight loss failure statistics

A 2001 study by Anderson et al. concluded that five years after completing a structured weight loss programme of dietary changes and exercise schedules, participants maintained an average weight loss of 3kg and a typical weight reduction of almost 3.2% compared to their initial body weight.

Average weight loss maintenance statistics

	All	Men	Women
Years of follow-up	4.4	4.4	4.4
No. of studies	13	6	5
No. of subjects	1,081	247	534
Average initial weight (kg)	98	115	95
Average weight loss (kg)	14.00	18.30	16.60
Average weight loss maintenance (kg)	3.00	4.70	4.66
Average percentage weight loss maintenance (%)	23.4%	30.5%	23.6%
Average reduced weight percentage (%)	3.15%	4.48%	4.67%

(Source: Anderson et al., 2001)

Before the experiment, men registered an average initial weight around a fifth (21.1%) greater than women.

However, the results showed that:

Average weight loss was approximately a tenth (10.2%) greater for men than for women (18.3kg vs. 16.6kg)
This varied from 6.2kg to 44.2 kg for men and 3.5kg to 37.9kg for women, a range of 38kg and 34.4kg, respectively
Average weight loss maintenance was marginally higher for men (4.7kg) compared to women (4.66kg), although not statistically significant

Similarly, a 2019 study by Hall and Kahan found that substantial weight loss is possible across a range of treatments, but long-term, sustained weight loss is much more challenging. Their meta-analysis of 29 long-term weight loss studies found that more than half of the participants had put their lost weight back on within two years. By year five, 80% of the lost weight was regained.

"As a pharmacist, I see countless patients who've successfully lost weight but struggle with keeping it off long-term. The reality is that initial weight loss and maintenance are entirely different challenges.

After losing weight, our bodies work to regain it. Our metabolism slows down, meaning we burn fewer calories than we did before losing weight. This makes it much easier to regain weight if we return to our previous eating habits. At the same time, hunger hormones like ghrelin increase, whilst hormones that make us feel full decrease, leading to a stronger appetite and more frequent cravings.

The psychological aspect is equally challenging. The motivation and novelty that drives initial weight loss often fades over time. Many patients tell me they feel constantly hungry or find themselves reverting to old eating patterns when stress or significant life events occur.

Weight maintenance requires a permanent lifestyle shift, not a temporary diet. It's about developing sustainable diet and exercise habits, managing stress, ensuring adequate sleep, and seeking ongoing support if needed."

Jason Murphy (Head of Pharmacy at Chemist4U)

The most popular ways to lose weight in the UK

According to a weight loss statistics report by Ipsos, just under half (46%) of those surveyed plan to exercise more regularly, making it the most popular way for people to lose weight in the UK for 2025. This was followed by just over two-fifths (42%) of those who claimed they would eat healthier throughout the year to shed some pounds.

Most popular ways to lose weight in the UK (2025)

Incidentally, just over a quarter of people said they would drink more water (28%) and/or diet/reduce calorie consumption (26%) in 2025 as their main way of losing weight across the year.

Most popular weight loss programmes based on search volumes (exclusive data)

As of May 2025, Second Nature was the most popularly searched weight loss programme (index score 55) based on Google Trends data. This made it around a quarter more popular (27.9%) compared to MyFitnessPal in second.

The shift of interest between June 2024 and May 2025 compared to June 2023 and May 2024 is as follows for the various weight loss programmes:

Noom (-50%)
NHS Weight Loss Plan (-2%)
NHS Digital Weight Loss Programme (-4%)
Second Nature (+13%)
MyFitnessPal (+20%)

Other available weight loss plans also recorded declining popularity between 2023-25, including the Mayo Clinic Diet (-37%), Slimming World (-22%), and Man v Fat Football (-32%). This suggests people are starting to turn away from more traditional, mainstream methods of losing weight.

Should current trends continue, interest in MyFitnessPal is expected to decrease by almost two-fifths (-39.5%) between May 2025 and December 2026. Conversely, the number of people searching for the NHS Digital Weight Management Programme is anticipated to increase by more than a quarter (+29.2%) during the same period.

Weight loss injection statistics

GLP-1 receptor agonists, such as Wegovy and Mounjaro, have now emerged as potential treatments for weight loss. Clinical trials suggest that patients may lose around 14-20% of their body weight within a year of starting their medication, with other weight management treatments due to enter the market once they pass clinical trials.

Self-administered, injectable weight loss drugs are now available across digital platforms and in-store pharmacies. As a result, the General Pharmaceutical Council (GPhC) updated its guidance in February 2025 that requires online pharmacies to gain independent verification of a patient’s weight, height, and BMI before prescribing weight loss medication.

For those with severe obesity, surgical interventions provide an alternative weight loss solution. For example, gastric bypass surgery is shown to produce a significant loss of 60-80% of excess body weight.

However, studies have also found that between 15-35% of patients regain a significant amount of weight or fail to achieve sufficient weight loss after surgery (defined in this case as less than 50% excess weight loss or having a BMI of more than 35).

As the number and variety of non-surgical weight loss solutions have increased, this has resulted in a drop of around four-fifths (80%) for private bariatric surgeries as people look to alternatives for losing weight.

The escalating demand for weight loss medication has resulted in some substantial investments to expand manufacturing capabilities and distribution networks. For example, Novo Nordisk budgeted £6.8 billion in 2024 to keep production lines operating 24/7 and grow their facilities further.

Where do most people learn about weight loss injections?

According to our survey results, around a third of people tend to learn about weight loss injections from friends and family and/or their doctor.

Main sources of information for weight loss injections

Furthermore, more than a quarter of those questioned claim to turn to online media and/or social media adverts for details about weight loss injections.

“This data reveals some positive trends in how people are approaching weight loss injections in the UK. It's encouraging to see people gaining information from a variety of sources to help make informed decisions about their weight management.

However, what is concerning is that only a third of those surveyed are consulting their doctor as the main source of information about weight loss injections. This means patients are potentially missing crucial medical guidance about contraindications, side effects and proper monitoring.

While friends, family, and social media can provide useful insights into the use of weight loss medication, particularly from an anecdotal point of view, they are no replacement for sound medical advice based on scientific research and development.

Weight loss medications can be genuinely life-changing when used appropriately, but proper medical supervision from the outset makes all the difference to both patient safety and the treatment's long-term success.”

Ayesha Bashir (Prescribing pharmacist and Chemist4U)

Mounjaro and weight loss jab advice on TikTok (exclusive data)

Chemist4U analysed the top 100 performing TikTok videos containing relevant weight loss jab advice hashtags.

Findings suggest that more than two-thirds (69%) provide health advice, with just over a quarter of these encouraging people to do research.

Table 4: Percentage of TikTok videos that apply to different elements of Mounjaro and weight loss jab advice

Statement	Percentage of videos
Featuring a discount code for viewers to use	4%
Providing disclaimers when explaining/showing how to administer jabs	5%
Pushing or selling an additional product	14%
Influencing viewers to visit an external shop	14%
Including relevant disclaimers	18%
Explaining or showing how to administer weight loss jabs	18%
Providing disclaimers when providing health advice	19%
Encouraging visitors to do their own research	21%
Encouraging research when providing health advice	26%
Sharing the weight they've lost	30%
Providing health advice	69%

(Source: Chemist4U)

Of all videos analysed, around one in five explained or showed the user how to administer weight loss jabs, with just one in 20 of these providing relevant disclaimers.

For more information, check out our comparative guide of Wegovy vs. Saxenda to see how much weight you could lose between the two, how often you’ll need to inject, and much more.

Most popular weight loss injections

Consumer research by Ipsos in 2024 found that almost two-thirds (64%) of respondents knew not very much or nothing at all about weight loss injections.

Figure 6: Public awareness of weight loss injections in the UK by age group

The percentage of those who knew a great deal/fair amount decreased with age, with almost double the proportion of 18-34-year-olds claiming to have a solid understanding of weight loss medications compared to those in the 55-75 age bracket.

Almost four-fifths (79%) of the oldest age group knew very little about weight loss injections compared to just under half (49%) of the 18-34 cohort.

For further information, check out our guide on who can take Wegovy, what the benchmarks are, who should not be taking this medication, and what Wegovy dosage is right for you.

Figure 7: Most popular weight loss injections based on search volumes (exclusive data)

As of May 2025, Mounjaro and Zepbound were the most commonly searched weight loss drugs, with an index score of 100 according to Google Trends data. This made them around a fifth (20.5%) more popular than Wegovy in second place.

The shift of interest for these weight loss medications between June 2024 and May 2025, compared to June 2023 and May 2024, was as follows:

Mounjaro (+1,721%)
Zepbound (+150%)
Ozempic (+36%)
Wegovy (+14%)
Saxenda (-70%)

Based on our predictions, Mounjaro and Zepbound are expected to retain their crowns as the most searched weight loss injections by December 2026. Should current trends continue, Wegovy and Ozempic are anticipated to grow in popularity by 6.0% and 6.5%, respectively.

Note: Zepbound is only prescribed in the US and is the brand name for the drug tirzepatide when prescribed for weight loss.

What is the most popular weight loss injection?

This will depend on your definition of most popular. According to our analysis of Google Trends data, Mounjaro and Zepbound were the most commonly searched weight loss drugs (as of May 2025).

Average weight loss on Mounjaro

GLP-1 medicines are weight-loss medications that mimic the actions of glucagon-like peptide-1 (GLP-1). This can have several effects on the body, such as reducing appetite and helping the body to produce more insulin to regulate blood sugar levels.

Tirzepatide is a weight loss medicine within the GLP-1 category and is available on the market as a branded product called Mounjaro.

In November 2023, the Medicines and Healthcare products Regulatory Agency (MHRA) approved tirzepatide for weight loss in adults aged 18 years and above, having already been licensed for the treatment of type 2 diabetes in adults just 13 months earlier.

Guidance from the National Institute for Health and Care Excellence (NICE) on the use of tirzepatide in the NHS states that it should be made available to adults with:

A BMI of at least 30kg/m² for those registered as obese and between 27-30kg/m² for those classed as overweight (with a lower threshold for those from ethnic minority backgrounds)
At least one weight-related comorbidity.

Facts about weight loss and Mounjaro

Mounjaro is available for weight management as a pre-filled injection pen, containing between 2.5mg and 15mg of tirzepatide in increments of 2.5mg. The starting dose is 2.5mg once a week for four weeks, increasing to 5mg once a week. From here, the dose may then be increased in at least four-week intervals up to the maximum dose of 15mg once per week (if recommended by a doctor).

The new weight management indication is based on the outcomes of two international clinical trials called SURMOUNT-1 and SURMOUNT-2. These randomised, double-blind, placebo-controlled studies involved overweight and obese adults both with and without diabetes.

In SURMOUNT-1, more than 2,500 obese/overweight adults with at least one weight-related comorbidity (not diabetes) were given weekly doses of either 5mg, 10mg, or 15mg tirzepatide or a placebo over 72 weeks.

The average percentage change in weight over this period was:

-16.0% for 5mg
-21.4% for 10mg
-22.5% for 15mg
-2.4% for placebo

Furthermore, 89.4% (5mg), 96.2% (10mg), and 96.3% (15mg) of patients on tirzepatide lost at least 5% body weight compared to just over a quarter (27.9%) of those on the placebo. This means those on SURMOUNT-1 tirzepatide lost more than three times as much weight compared to those taking the placebo.

In SURMOUNT-2, almost 1,000 obese/overweight adults with type 2 diabetes were given either 10mg or 15mg tirzepatide or a placebo every week over 72 weeks.

The average percentage change in weight over this period was:

-13.4% for 10mg
-15.7% for 15mg
-3.3% for placebo

In addition, 81.6% (10mg) and 86.4% (15mg) of those taking tirzepatide lost at least 5% body weight compared to less than a third (30.6%) for the placebo. This means those on SURMOUNT-2 tirzepatide lost between 2.6 and 2.8 times as much weight compared to those on the placebo.

Did you know?

The food you consume while taking Mounjaro could have a significant impact on the degree to which your outcomes are successful. Check out our guide on what to eat and what to avoid when taking Mounjaro.

Average weight loss on Mounjaro vs. other weight loss medications

When it comes to weight loss statistics between various medications, results can vary depending on multiple factors, including the type of drug, the dosage, and the duration over which it is taken.

Average weight loss statistics across different weight loss injections

Treatment	Dosage	Approved for	How much weight can you lose?
Wegovy (Semaglutide)	Once per week	Weight loss	Up to 14.9% (in 68 weeks)
Saxenda (Liraglutide)	Once per day	Weight loss	Up to 6.3% (in 56 weeks)
Mounjaro (Tirzepatide)	Once per week	Weight loss and type 2 diabetes	Up to 22.5% in 72 weeks

(Source: Chemist4U)

According to summarised research findings from Chemist4U, average weight loss could vary between 6.3% for Saxenda (liraglutide) over a 56-week period, up to 22.5% for Mounjaro (tirzepatide) over 72 weeks.

This means, in theory, people could lose up to three times more weight on Mounjaro than Saxenda. However, results will likely vary from person to person.

For more information, check out our guide on how Saxenda works, what it is, and how it can help contribute to a successful weight loss journey.

Mounjaro average weight loss vs. typical weight loss on Wegovy

Weight loss statistics from Chemist4U show that more than four in five (83%) adults taking Wegovy for 68 weeks lost at least 5% of their body weight compared to just under a third (31%) taking a placebo.

Other results show that, after 68 weeks:

Two-thirds (66%) of those on Wegovy lost 10% or more of their weight compared to 12% for the placebo drug
Just under half (48%) of Wegovy patients lost at least 15% of their original body weight compared to just 5% from the placebo group.
Adolescents aged 12 and above saw a reduction of more than a sixth (16.1%) in BMI compared to a 0.6% fall with the placebo.
Around three-quarters (77%) of those in the Wegovy group had a BMI reduction of at least 5%, compared to a fifth (20%) in the placebo group.

Based on a 2024 weight loss study published in JAMA Internal Medicine, patients taking tirzepatide were more than twice as likely to achieve an average weight loss of 10% or more. They were also three times as likely to lose at least 15% of their original weight compared to those on semaglutide.

Further results indicate that:

At three months, the average weight loss on Mounjaro (tirzepatide) was 5.9% compared to 3.6% for semaglutide.
After 12 months, patients on tirzepatide lost more than 15% of their original body weight. The respective figure for semaglutide was around half, at 8%

The SURMOUNT-5 clinical study in 2024 revealed a 47% greater relative weight loss compared to Wegovy's typical weight loss after a 72-week trial.

Participants using both medications lost significant amounts of weight, with those on Mounjaro (tirzepatide) experiencing an average weight loss of 20.2% (22.8kg) of body weight compared to those on Wegovy (semaglutide), who averaged a loss of 13.7% (15kg).

The findings, published in the New England Journal of Medicine and presented at the European Congress on Obesity in Malaga (Spain), also showed:

Around a third (31.6%) of people lost a quarter of their body weight using Mounjaro compared to a sixth (16.1%) on Wegovy
Patients on Mounjaro reduced their waistlines by an average of 18.4cm compared to 13cm on Wegovy
Those on Mounjaro reported better blood pressure, blood sugar, and cholesterol levels compared to recipients of Wegovy
Both had similar levels and degrees of side effects
Women recorded a higher average weight loss compared to men across both drugs

For more information, check out our guide on how semaglutide works when it comes to weight loss.

Mounjaro vs. Ozempic weight loss statistics

A weight loss study published on medRxiv revealed that just over two-fifths (42.3%) of those taking tirzepatide (the main ingredient in Mounjaro and Zepbound) lost at least 15% of their weight compared with just under a fifth (19.3%) of those taking semaglutide (the active ingredient in Ozempic and Wegovy).

Feature image with the title 'UK Weight Loss Statistics Report' and an image of a set of scales, next to a lettuce leaf, apple, and tape measure

Accounting for individual risk factors, those on Mounjaro were around:

Three-quarters (76%) are more likely to lose at least 5% of their body weight compared to patients taking Ozempic
More than twice as likely to lose at least 10% of their body weight compared to those on Ozempic
Around three times more likely to lose at least 15% of their body weight compared to Ozempic users

An analysis of electronic health records and pharmacy dispensing data of almost 9,200 patients receiving Mounjaro and a similar number taking Ozempic revealed that, after three months of treatment, patients on Mounjaro lost an average of 2.3% more weight than those on Ozempic. By six months, the gap had widened to 4.3%, and by 12 months, this had reached 7.2%.

What is the best injection for weight loss?

According to findings from Chemist4U, the most effective weight loss injections on the market as of 2025 are Mounjaro and Wegovy, with an average weight loss of 14.9% and 22.5%, respectively. However, the best injection may vary from person to person. Therefore, you should seek professional medical advice before deciding which one is right for you.

Weight loss injection success rates

The GLP-1 landscape is a dynamic space, with pharmaceutical companies continuing to push the boundaries of scientific research and development to help bring various weight loss medications to the market.

Average weight loss statistics across different GLP-1 medications

Company	Drug name	Clinical trial phase	Study length	Average weight loss percentage achieved (%)
Roche	CT-388	Phase 1b	24 weeks	18.8%*
Roche	CT-868	Phase 2	24 weeks	> 5%
Roche	CT-966*	Phase 1	4 weeks	Around 6.1%
Terns	TERN-601*	Phase 1	28 days	5.5%*
Viking	VK2735	Phase 2	13 weeks	Up to 14.7%
Viking	VK2735*	Phase 1	28 days	Up to 8.2%
Novo Nordisk	Amycretin*	Phase 1	12 weeks	Up to 13.1%
Novo Nordisk	Ozempic	Approved	68 weeks	15.1%
Novo Nordisk	Wegovy	Approved	68 weeks	15%
Pfizer	Danuglipron*	Phase 2b	32 weeks	8-13%
Lilly	Tirzepatide	Approved	72 weeks	24.5%
Lilly	Orforglipron*	Phase 2	36 weeks	Up to 14.7%

(Sources: Roche, Terns Pharmaceuticals, Viking, Reuters, Novo Nordisk, Wegovy, Pfizer, NLM, Lilly)

Further findings from scientific research and development into weight loss medication include the following case studies:

A 2024 weight loss study found that opioid users experienced a 40% lower overdose rate after administering GLP-1s, with a similar benefit (50%) for those suffering from alcohol misuse.

Roche also presented findings at the 2024 European Association for the Study of Diabetes (EASD) conference in Madrid on the development of its GLIP-1 programmes.

Their research showed:

A placebo-adjusted average weight loss of almost a fifth (18.8%) in Phase 1b trials for CT-388 (an injectable GLP-1/GIP agonist)
An average weight loss of 7.3% over four weeks in Phase 1 clinical trials for CT-966 (an oral small molecule)

Terns announced data in 2024 on TERN-601, highlighting a statistically significant, placebo-adjusted mean average weight loss of up to 4.9% over 28 days in a Phase 1 study. Just over two-thirds (67%) of patients on the highest dose reported a reduction of at least 5% of their starting body weight during this period.

In their Phase 1 study, Viking’s VK2735 (an oral weight loss pill) displayed a dose-dependent, placebo-adjusted average weight loss of up to 3.3% over 28 days. That said, in the Phase 2 VENTURE study lasting 13 weeks, subcutaneous doses of VK2735 produced a placebo-adjusted average weight reduction of up to a seventh (13.1%).

During Phase 2b trials, participants taking Pfizer’s danuglipron (an oral GLP-1 agonist) exhibited a placebo-adjusted, average weight loss ranging between 8-13% over 32 weeks, with a discontinuation rate of more than 50%.

Note: Once you have reached your weight loss goals with injections such as Mounjaro and Wegovy, an important consideration is maintenance dosing. This will help you manage your weight loss for the long term by working with your prescriber to maintain your progress.

Average weight loss on Mounjaro

According to a clinical trial presented in April 2025, Mounjaro users typically sustain weight loss for three years.

Data was collected for 700 patients using three different doses of tirzepatide over 176 weeks, all of whom were diagnosed as obese/overweight and had pre-diabetes.

The results show participants tended to experience one of three patterns of weight loss:

Steady (average body weight reduction of 9.2%)
Medium (average weight reduction of 20.2%)
Rapid (average weight reduction of 30.8%)

Researchers claim that most Mounjaro patients achieved clinically meaningful weight loss throughout the study, with the average time to reach the lowest weight being 22 months. At this point, participants typically had lost almost a quarter (23.1%) of their starting weight.

While some patients regained their lost weight by week 176 (despite continuing their course of medication), the average weight reduction from their starting weight still stood at just under a fifth (19.4%) by the end of the study.

“Most patients get stomach problems - feeling sick, stomach pain, or changes in bowel movements — especially in the first few weeks after starting weight loss injections.

I always ensure patients know these reactions are normal and can be handled. We can use medications like macrogol sachets for constipation, or manage symptoms by eating smaller meals, avoiding fatty or spicy foods, drinking plenty of water, and increasing the amount of natural fibre in your diet. We advise patients to report back to us if these side effects are persistent or do not respond to the self-help measures mentioned.

Using your injection on the same day each week helps your body get used to it. Many patients also find it helpful to write down what they eat and how they feel afterwards, so it's easier to know what might trigger their side effects.

I often see people give up on their treatment too early because of side effects. These symptoms can be unpleasant but usually improve as your body adjusts to the medication, typically within four to six weeks. I stay in regular touch with patients and work with their GP when needed to ensure they're tolerating the treatment well.

The gradual dose increase - what we call titration - is crucial here. Starting with a lower dose and slowly building up over several months gives your body time to adapt. This isn't about delaying results; it's about making the treatment tolerable so you can stick with it long-term.

You'll work with your prescriber to decide when it's the right time to increase your dose, with side effects and how much weight you've lost both playing a part.

These medicines need patience and realistic expectations, but with the proper support, I've seen remarkable improvements in people's health and daily lives.

Ian Budd (Prescribing pharmacist at Chemist4U)

A 2025 weight loss study published in the Nature Medicine journal found that after an average of 3.68 years, those taking GLP-1 agonists had a lower risk of developing 42 different diseases from a possible 175 (compared to those receiving their usual medicines).

Research findings highlight the following reduced risk for recipients of GLP-1 weight loss medications:

Liver failure (24%)
Respiratory issues (22%)
Cardiac arrest (22%)
Alzheimer’s disease (12%)
Heart failure (11%)
Heart attack (9%)
Ischaemic stroke (7%)

For more information, check out our guide on the benefits of Wegovy and Mounjaro beyond weight loss.

Previous academic studies, such as that published in the New England Journal of Medicine in 2023, somewhat support these findings.

Their analysis of more than 17,600 people found that those given semaglutide had a 20% lower risk of developing a heart attack or stroke or dying from coronary heart disease (CHD), compared to those given a placebo injection after 2.75 years.

That said, those taking GLP-1 agonists did experience higher risks of 19 side effects or diseases compared to those on their usual medication.

Participants were almost 2.5 times more likely to develop drug-induced acute pancreatitis, with vomiting, arthritis, and low blood pressure displaying an increased risk of 30%, 11%, and 6%, respectively [45].

Did you know?

A 68-week weight loss study in 2024 found that once-weekly semaglutide injections in people with obesity and knee osteoarthritis resulted in an average weight loss of 13.2% from baseline weight compared to 3.2% on a placebo. This almost mirrors the outcomes for Kosiborod et al. in 2023, who concluded a mean weight loss of 13.3% in obese patients at risk of heart failure compared to 2.3% for a placebo drug.

Weight loss research and development (R&D) timeline

The weight loss R&D movement was kick-started by the introduction of Saxenda towards the end of 2014. Launched by Novo Nordisk, this was the first GLP-1 drug approved for obesity and yields an average weight loss of 7% over 12 months.

The table below highlights some of the major developments in the world of weight loss medication and some changes that have taken place between 2014-25.

Key events in the development of weight loss medication over time

Date	Headline	Details
23/12/14	Initial launch of Saxenda (liraglutide) by Novo Nordisk	The first GLP-1 drug approved for obesity. A twice-daily injectable averaging 7% weight loss over a year at a cost of around $1,000 a month (launch price)
27/11/20	Rhythm Pharmaceuticals announces FDA approval of IMCIVREE (setmelanotide) as the first-ever therapy for chronic weight management in patients with obesity due to POMC, PCSK1, or LEPR deficiency.	Treatment is indicated for adults and pediatric patients aged six and above with obesity due to POMC, PCSK1, or LEPR deficiency. Based on two 52-week trials that resulted in statistically significant weight loss and reduction of hunger. Four in five (80%) patients with obesity due to POMC or PCSK1 deficiency and more than two in five (45.5%) with LEPR deficiency achieved greater than 10% weight loss after 12 months of treatment.
04/06/21	Initial launch of Wegovy (semaglutide) by Novo Nordisk	Approval of Ozempic for diabetes and Wegovy for obesity, showing nearly 10% weight loss over two years. Costing around $1,350 per month (launch price).
08/11/23	Initial launch of Zepbound (tirzepatide) by Eli Lilly	Average 20% weight loss over 72 weeks Around $1,100 a month (launch price).
07/02/24	Innovent’s first new drug application of mazdutide for chronic weight management was accepted by the NMPA in China.	New Drug Application (NDA) for mazdutide was accepted by the Centre for Drug Evaluation (CDE) for China’s National Medical Products Administration (NMPA) for chronic weight management of obese/overweight adults. First GLP-1R/GCGR dual agonist to successfully pass Phase 3 trials following an NDA submission. Mazdutide at 4mg and 6mg doses resulted in average weight loss of 15% at 48 weeks.
24/04/24	Lilly receives European marketing authorisation for tirzepatide (Mounjaro)	The European Commission (EC) granted marketing authorisation for tirzepatide (Mounjaro) solution for injection of a multi-dose, pre-filled pen (KwikPen) for two situations: The treatment of adults with uncontrolled type 2 diabetes For weight management in adults with a BMI above or equal to 30kg/m2, with at least one weight-related comorbidity, partnered with a reduced calorie intake and increased physical activity.
20/09/24	Novo Nordisk A/S: Monlunabant phase 2a trial in obesity successfully completed	Investigation into the efficacy and safety of a once-daily, 10mg, 20mg, and 50mg dose of monlunabant compared to a placebo. The trial took place with 243 people with obesity and metabolic syndrome over 16 weeks. With a mean average baseline body weight of 110.1kg, all doses achieved a statistically significant weight loss compared to the placebo. After 16 weeks, those on the 10mg dose achieved an average weight loss of 7.1kg (vs. 0.7kg for the placebo). The most commonly reported adverse effect was gastrointestinal, with the majority being mild to moderate and dose-dependent.
20/12/24	Novo Nordisk A/S: CagriSema demonstrates significant weight loss in obese/overweight adults in the REDEFINE 1 trial	REDEFINE 1 is a 68-week programme testing the efficacy and safety of subcutaneous CagriSema (a fixed dose combination of cagrilintide 2.4mg and semaglutide 2.4mg) compared to the administration of individual components and placebo. Included 417 randomised people with obesity or classed as overweight with one or more comorbidities and a mean average baseline body weight of 106.9kg. The result was a statistically significant weight loss at week 68 with CagriSema vs. the placebo (22.7% vs. 2.3%). Those on cagrilintide 2.4mg experienced an average weight loss of 11.8% compared to 16.1% for those on semaglutide 2.4mg. Just over two in five (40.4%) patients on CagriSema achieved a weight loss of 25% or more after 68 weeks compared with 6% for cagrilintide 2.4mg, 16.2% for semaglutide 2.4mg, and 0.9% for the placebo. The most commonly reported adverse effect was gastrointestinal, with the majority being mild to moderate and diminished over time.
17/01/25	Novo Nordisk A/S: Semaglutide 7.2mg achieved 20.7% weight loss in the STEP UP obesity trial and 18.7% regardless of treatment adherence	STEP UP is a phase 3b trial in the global STEP programme and involves a 72-week trial to test the efficacy and safety of weekly administering a subcutaneous semaglutide 7.2mg compared to semaglutide 2.4mg and placebo. The trial involved 1,407 randomised adults with obesity. The result was a statistically significant weight loss at week 72 for semaglutide 7.2mg versus the placebo. With a mean average baseline body weight of 113kg, the average weight loss for those receiving semaglutide 7.2mg was 20.7% after week 72, compared to 17.5% for semaglutide 2.4mg and 2.4% for placebo. Around one in three (33.2%) receiving semaglutide 7.2mg achieved a weight loss of at least 25%, compared to 16.7% for semaglutide 2.4mg and 0% for placebo. The most commonly reported adverse effect was gastrointestinal, with the majority being mild to moderate and diminished over time.
24/01/25	Novo Nordisk successfully completes phase 1b/2a trial with subcutaneous amycretin with 125 people classed as overweight.	The trial combined single and multiple ascending doses with three different amounts over 36 weeks. Those with a mean average body weight of 92.7kg achieved an estimated body weight loss of 9.7% on 1.25mg (20 weeks), 16.2% on 5mg (28 weeks), and 22% on 20mg (36 weeks). Those treated with a placebo experienced respective estimated body weight gains of 1.9%, 2.3%, and 2.0%. The most commonly reported adverse effect was gastrointestinal, with the majority being mild to moderate.
10/03/25	Novo Nordisk A/S: CagriSema shows significant weight loss in overweight adults and those with type 2 diabetes in the REDEFINE 2 trial	REDEFINE 2 is a Phase 3 trial of the global REDEFINE programme Took place over 68 weeks and aimed to test the efficacy and safety of once-weekly subcutaneous CagriSema compared to a placebo. Involved 1,205 randomised people classed as obese/overweight with type 2 diabetes and a mean average body weight of 102kg. The result was a statistically significant weight loss compared to those on the placebo. Mean average weight loss of 15.7% vs. 3.1%. Weight loss of 5% or more after 68 weeks was achieved by almost nine in 10 (89.7%) of patients on CagriSema vs. just under one in three (30.3%) by placebo. The most commonly reported adverse effect was gastrointestinal, with the majority being mild to moderate and diminished over time.
14/04/25	Pfizer announces plans to discontinue development of danuglipron	Outcomes of Pfizer’s dose-optimisation studies of once-daily administrations of danuglipron (an oral GLP-1 receptor agonist) met key pharmacokinetic objectives, with the potential for efficacy Phase 3 testing. Of the 1,400 people who took part in the study, a single, asymptomatic participant experienced a potential drug-induced liver injury which resolved after the discontinuation of danuglipron. In light of this, Pfizer decided to cease all further development of the molecule.

(Source: Ozmosi, Novo Nordisk, Pfizer, Lilly, PR Newswire, and IQVIA)

Public attitudes towards weight loss injections

According to survey data from Ipsos, one in 20 (5%) UK adults questioned in 2024 had used a weight loss injection at some point in their life.

Percentage of people who have taken weight loss injections in the UK

Incidentally, less than one in 10 (9%) people knew of family or friends who had taken weight loss medication, with almost five in six respondents (84%) claiming to have never used them before.

Should the NHS offer weight loss injections to people who are obese?

Market research by Ipsos shows that almost two in five (38%) UK adults surveyed in 2024 felt the NHS should not offer weight loss injections to those diagnosed as obese, with just over one in three (34%) of the opinion that they should.

How do people feel about weight loss injections? (exclusive data)

Almost nine in 10 of those surveyed by Chemist4U felt that their quality of life improved after using weight loss injections.

Just over half felt that this improvement was significant compared to less than two in five who acknowledged a slight improvement.

How has the use of weight loss injections affected your quality of life?

Conversely, just 2.3% believed their quality of life had decreased since taking weight loss injections.

In what ways has your quality of life changed since using weight loss injections?

Response	Percentage of respondents (%)
I feel more confident in my appearance	55.28%
I feel more confident and comfortable in public	50.71%
I have more energy	49.73%
I'm more physically active or mobile	47.01%
My mood or mental health has improved	46.68%
I sleep better	42.22%
I feel more confident dating or being intimate	34.17%
I experience less pain or discomfort	32.10%
I've saved money by eating less or having fewer meals	29.27%
My sex drive has increased	28.18%
I have experienced negative or unwanted side effects (e.g. nausea, vomiting, or digestive issues)	1.85%
My relationship with food has worsened (e.g. fear of eating, food guilt, disordered eating patterns)	1.09%
My mood or mental health has worsened	0.65%
I feel more anxious or obsessive about my weight or appearance	0.65%
The cost or accessibility of treatment is stressful or unsustainable	0.44%
Other, please specify	0.33%
Prefer not to say	0.22%

(Source: Chemist4U)

Since using weight loss injections, more than half of the respondents to our survey noted a boost in confidence when it came to their appearance and how comfortable they felt in public.

Our findings also show that almost half of the people reported higher energy levels and feeling more physically active/mobile since taking this medication, with more than two-fifths claiming they now sleep better.

Incidentally, less than 2% of respondents claimed to experience negative or unwanted side effects, such as nausea, vomiting, or digestive problems.

What, if anything, describes your perception of weight loss injections?

Response	Percentage of respondents (%)
Effective	37.7%
Safe	31.0%
Recommended by doctors	29.0%
Long-term results	26.9%
Manageable side effects	26.9%
Prescription necessary	25.5%
Can be effective	23.7%
Affordable	21.5%
Quick fix	21.4%
Too expensive	20.8%
More widely available	20.6%
Available over the counter	12.4%
Natural alternatives effective	11.9%
Restricted availability	11.7%
Severe side effects	8.4%
Not safe	4.2%
Not effective	2.5%
I do not have a perception of weight loss injections	1.1%
Other, please specify	0.4%

(Source: Chemist4U)

Based on recent survey results, the most common perception of weight loss injections is that they are effective, noted by almost two-fifths of respondents. This was contrasted by 2.5% who believe they are not effective.

This was followed by around three in 10 who feel weight loss injections are safe and recommended by doctors, compared to less than one in 25 who deem them unsafe.

What, if anything, best describes how people have treated you differently since using weight loss injections?

Response	Percentage of respondents (%)
I've noticed significantly more respect or attention	26.3%
I've noticed a little more respect or attention	21.7%
I've received a mix of positive and negative treatment	18.0%
N/A - People treat me the same	16.4%
I feel people now assume things about me (e.g. personality, discipline)	13.2%
I've experienced only negative treatment (e.g. jealousy, judgment)	3.9%
Other, please specify	0.3%
Prefer not to say	0.3%

(Source: Chemist4U)

Since taking weight loss injections, almost half of the respondents to our survey noticed a greater degree of respect or attention from other people. This is contrasted by around one in 25 who have experienced only negative treatment.

Almost a fifth claim to have received a mixture of positive and negative responses from others, with around a sixth feeling people treat them the same as before.

Attitudes towards weight loss injections in the media (exclusive data)

Based on our analysis of MuckRack data, Mounjaro, Wegovy, and Ozempic were the most talked-about weight loss injections between 2020-25, each with over 18,000 articles in the space of five years.

Sentiment analysis of different weight loss injections in the media

In summary:

Sentiment towards these three injections is generally negative, with the smallest gap between positive and negative articles for Mounjaro (40% vs. 45%, respectively)
More than four in five of the articles analysed about lipotropic injections were deemed positive, compared to more than three in five for Saxenda, which contained a negative sentiment.
On average, an almost identical proportion of articles analysed were positive (41%) compared to negative (42%)

Sentiment analysis of different weight loss injections in the media for total engagement*

According to our sentiment analysis of MuckRack data, almost a third (32%) of articles shared, commented on, or linked on social media about weight loss injections were deemed positive, compared to more than half (54%) for negative.

The largest gap in total engagement statistics was seen for Mounjaro, where almost three in four articles were categorised as negative, compared to less than one in 20 for positive.

The trend of negative sentiment for total engagement towards weight loss injections was apparent for most medications, apart from Contrave, where almost three in five articles were perceived as positive compared to less than two in five for negative.

Sentiment analysis of different weight loss injections in the media for total Unique Visitors per Month (UVM)*

On average, positive sentiment articles on weight loss injections attract more than a quarter (26%) of individual visitors, while negative sentiment coverage accounts for more than half (52%).

This trend is largely mirrored in articles about specific weight loss injections, with the largest gaps in positive and negative total UVM existing between lipotropic injections (6% and 92%) and Saxenda (19% and 60%).

On the flip side, positive articles on Ozempic gained a third of individual visitor traffic between 2020-25, with negative coverage attracting just under half (48%). The gap in sentiment analysis data for positive and negative total UVM was almost identical for Cagrilintide (37% and 39%, respectively) and represented the smallest gap between the two in our study.

Sentiment analysis of different weight loss injections in the media over time

Our analysis of MuckRack data highlights various weight loss injection trends when it comes to sentiment in the media:

Between October 2024 and May 2025, the number of positive articles about Mounjaro has more than quadrupled (+347.9%) compared to negative ones, which have grown by more than a third (36.9%)
As of May 2025, there were almost a quarter (24.5%) more positive articles in the media compared to negative ones
The number of negative articles on Ozempic dropped by more than a quarter (28.8%) between January and May 2025, yet were almost four-fifths (79.8%) more common in the media compared to positive articles.
The number of positive and negative articles about Wegovy grew by more than 2,600% and 1,030%, respectively, between October 2024 and May 2025
There were around a quarter more positive and negative articles for Wegovy in May 2026 compared to Mounjaro.

Weight loss surgery statistics

Number of people having weight loss surgery in the UK

As of 2023-24, the number of people across England having weight loss surgery stood at 5,500. The vast majority of these (91%) were primary bariatric procedures.

Number of patients having different types of bariatric surgical procedures in England (2019-24)

Weight loss surgery statistics in England have fluctuated since 2019-20, from a peak of 6,500 down to 1,900 the following year, a decrease of 70%. This is likely due to the COVID-19 pandemic, where most non-essential hospital procedures were cancelled.

Since 2021-22, there has been a year-on-year rise in the number of weight loss surgeries across England, increasing by a quarter from 4,400 to 5,500 in the space of three years.

Weight loss surgery statistics in Scotland

According to a 2021 study by the National Institute for Health Research (NIHR), patients in Scotland who are being assessed for weight loss surgery have an average age of 47. This is around five years older than the international average age of 42. The mean BMI of Scottish patients at the time of bariatric surgery in 2021 was 42, typically around a seventh higher than those across other countries having the same treatment.

Figures published in 2020 showed that an average of four people per week in Scotland were having weight loss surgery on the NHS.

Weight loss surgery statistics in Wales

As of 2022-23, bariatric surgeons operated on 103 patients, resulting in an average of almost two per week.

The cumulative cost of these treatments, including inpatient care, was just over £867,000.

A survey by the Welsh government in the previous year found that almost two-thirds (63%) of the Welsh population were considered overweight, with a quarter classed as obese. Added to this, it’s estimated that the number of people in Wales with diabetes could rise by more than a fifth (+22%), or 260,000 people, by 2035-36. Therefore, this could cause the number of weight loss surgeries to increase across Wales in the coming years.

Average cost of weight loss surgery in the UK

As of 2025, the average cost of weight loss surgery in the UK starts from around £8,000, but this will depend on several factors, including:

The type of surgery
Location
How experienced the surgeon is
Any individual health needs or considerations.

Average starting cost of weight loss surgery in the UK

Generally speaking, gastric balloons are the cheapest form of weight loss surgery, with prices ranging from about £4,400 upwards.

By contrast, a gastric bypass is usually the most expensive type of weight loss surgery in the UK, typically more than double the average cost of a gastric balloon.

Note: These figures relate to the average cost of weight loss surgery via private practitioners. Some of these procedures may be available on the NHS if you meet certain criteria, such as:

A BMI of 40 or more
A BMI between 35-40 and a pre-existing condition that might improve after losing weight, such as high blood pressure, diabetes, arthritis, breathing issues, and asthma
You agree to make certain lifestyle changes and attend regular check-ups after your surgery

For more information, read our guide on what BMI you need for weight loss medication.

Weight loss surgery statistics from Qunomedical reveal the average cost of three different procedures in selected countries.

Their data shows:

The typical cost of a gastric band ranges between €4,500 in the Czech Republic and up to €12,300 in the US, and is generally the cheapest of the three procedures.
A gastric bypass is usually the most expensive weight loss procedure when compared to a sleeve and a band. This can range from an average cost of €5,800 in Lithuania up to €19,500 in the US (more than three times the amount)
The average cost of a gastric sleeve varies from €4,500 in Mexico up to €17,500 in the US

The average cost of different weight loss surgeries in the UK vs. other selected countries

Weight loss surgeries in the UK tend to be more expensive than in other countries.

For example:

The UK average cost of a gastric sleeve is around €10,000, more than double the typical price in Mexico and the Czech Republic, yet around two-fifths less (42.9%) than in the US
A gastric bypass could cost around €12,400 in the UK (more than double the average price in Lithuania, but almost over a third (36%) less than in the US)
Gastric band procedures in the UK typically cost around €6,800. This is around 50% more than the average cost in the Czech Republic, yet almost half the usual price compared to the US

"I understand why patients consider overseas options for weight loss surgery, often due to cost considerations or waiting times. However, it's important to be aware of certain factors that could affect your treatment outcomes.

When considering surgery abroad, the key difference often lies in healthcare standards and regulatory frameworks, which can vary significantly between countries. While many international facilities offer excellent care, others may not meet the rigorous standards you'd expect from regulated healthcare systems.

One of the most important considerations is continuity of care. Weight loss surgery requires ongoing support, particularly around medication management and nutritional monitoring. If complications develop after returning home, coordinating care between your overseas surgeon and local healthcare providers can prove challenging.

For those exploring international options, I'd recommend focusing on accredited facilities that meet international standards. Look for surgeons with proven experience in bariatric procedures and ask about their patient outcomes. Crucially, ensure there's a clear plan for post-operative support, including how medications and supplements will be managed long-term, as well as what to do if complications arise.

Consider the total cost beyond the initial procedure – factor in potential follow-up treatments, travel expenses, and any additional care that might be needed back home.

Whatever you decide, thorough research and realistic expectations about ongoing care requirements are essential for the best results, whether you choose treatment domestically or internationally."

Jason Murphy (Head of Pharmacy at Chemist4U)

For more information, check out our guide on funding your weight loss treatment and the potential payment options on offer when it comes to different weight loss injections.

Average NHS weight loss surgery waiting list

Getting weight loss surgery through the NHS is not always a straightforward process. The average waiting time can vary depending on where you live, how quickly your local NHS trust can process your referral and the level of demand.

Patients wanting weight loss surgery on the NHS could expect to wait at least 18 months for their procedure, with some areas experiencing longer delays due to funding constraints or abnormally high demand.

Most NHS trusts also require patients to complete a six to 12-month structured weight loss programme before exploring surgical options.

Weight loss surgery success rate

The number of Weight Management Service referrals across England generally declined throughout 2024, from a peak of 10,735 in January down to a low of 5,420 in December, a drop of almost 50% in the space of 12 months.

Referral figures fluctuated between March 2024 (6,850) and October 2024 (8,795) before dropping off by almost two-fifths (38.1%) in the final three months of the year.

Number of Weight Management Service referrals in England (2024)

Bariatric surgery success rates can vary depending on several factors, such as:

Pre-operative factors (e.g. BMI, initial weight, age, the presence of comorbidities, eating disorders, etc.)
Psychosocial factors (e.g. mental health status)
Surgical factors (i.e. the type of procedure and your surgeon’s level of experience/skill)
Post-operative factors (e.g. your diet and exercise programme, and attending regular check-ups)

Measuring the success of weight loss surgery is usually done by calculating the percentage of excess body weight that is lost.

The average success rate for bariatric surgeries is around:

50% for a gastric band
50-60% for a gastric sleeve
60-70% for a gastric bypass

However, research found that 50% of patients who underwent gastric bypass surgery regained their lost weight within 24 months of surgery, with figures higher for obese and severely obese patients.

According to the Cleveland Clinic, around nine in 10 people lose about 50% of their excess weight during bariatric surgery and keep it off. They suggest the average weight loss after a gastric bypass is around 70% of excess body weight, 80% for a duodenal switch procedure, and between 30-80% for a gastric sleeve over an 18-24 month period.

UCLA Health also found that, after 12 months, patients lose an average of 60-70% of their excess weight following a gastric sleeve operation, with weight loss statistics generally increasing over time.

They found that:

Most people were losing about a pound a day, providing an average weight loss of 10-20 pounds in the first two weeks after surgery
After three months, excess weight loss was typically between 35-45%
Six months after surgery, this figure stood at 50-60%
The majority of people reach their lowest weight 12-24 months after surgery
The overall success rate for a gastric sleeve stands at approximately 80-90%

Did you know?

According to the Laparoscopic and Endoscopic Surgery Institute, the average weight loss after gastric sleeve surgery is up to 80% of excess body weight after 18 months. They found that the average monthly weight loss after a gastric sleeve operation is around 20lbs (or five pounds a week). By month three, this figure rises to between 25% and 35% and after six months, could reach 55% excess body weight.

Weight management service statistics in Scotland

According to the most recent data available from Public Health Scotland:

39,452 adults and 3,405 children were referred to weight management and type 2 diabetes prevention services between 1 October 2019 and 30 September 2022
54% of adult referrals were in the most recent year (Oct 2021 – Sep 2022)
During this period, 50% were for Tier 2 and less than two-fifths (37%) were for Tier 3 services
More than one in four referrals (26%) were from the most deprived parts of Scotland, compared to around one in 10 (12%) from the least deprived.
Comparative figures for child referrals were 31% vs. 8%
Across all adult referrals, more than nine in 10 (93%) were considered obese or severely obese, with more than half (52%) categorised as severely obese

Weight management service statistics in Wales

As of 25th May 2023, it’s estimated that there were 894 patients on the weight management service waiting list in Wales.

Weight management service statistics in Northern Ireland

On 21st May 2025, Northern Ireland’s Health Minister Mike Nesbitt announced the go-ahead for a new Regional Obesity Management Service.

This service, the first of its kind, is likely to be introduced in early 2026 and will focus on community-based services where patients can access lifestyle support and obesity medication (if clinically approved).

Average weight loss statistics in the UK through exercise

Meta-analysis by O’Brien et al. of 33 datasets showing data beyond 10 years after bariatric surgery highlighted that at 20 years:

The average weight reduction of patients was 30.1kg
Excess weight loss stood at just under half (48.9%)
Total weight loss was just over a fifth (22.2%)

It was also discovered that bariatric surgery lowered the risk of cardiovascular mortality, particularly incidences of heart failure, myocardial infarction, and stroke, but not atrial fibrillation.

One study demonstrated that in non-surgical obese patients, a 20% weight loss was needed (although rarely achieved) to decrease the long-term likelihood of major cardiovascular events from happening. In contrast, the respective figure for surgical patients was 10% and was usually accomplished quite easily.

Other findings from the paper show that post-bariatric surgery:

Diabetes was cured in more than three-quarters (76.8%) and improved in 86% of patients
Sleep apnoea was cured in 85.7% and improved in 83.6% of people
Participants suffering from hypertension were cured in more than three-fifths (61.7%) of cases and improved in 78.5%
Mortality rates following surgical complications ranged from 0% to 0.64%

A 2024 review of academic studies found that two-and-a-half hours of physical exercise per week could have a significant impact on how much weight people lose.

It found that those doing 30 minutes of exercise a week achieved only a modest reduction in body weight, whereas those doing more than 150 minutes per week at moderate intensity or greater saw a clinically important reduction in weight loss.

Previous studies have suggested the optimum period of exercise for weight loss is between 30 and 45 minutes per week. However, health guidelines suggest that a minimum of 150 minutes of aerobic exercise a week at moderate intensity could result in a meaningful weight loss of 2-3kg. Some research even suggests 225-420 minutes of moderate intensity physical activity could result in an average weight loss of 5-7.5kg.

NHS weight loss app statistics

A peer-reviewed paper published in the Obesity Journal in 2024 concludes that the NHS Digital Weight Management Programme helps patients to lose more than eight pounds on average once they are referred to the service.

Analysis shows almost 64,000 people were referred to the programme in its first year, with 50% taking up the offer and joining the service.

Of the 14,268 that completed the programme between April 2021 and March 2022, average weight loss was 3.9kg (8.59lbs) over 12 weeks. This was almost twice as much as those who started the programme but did not complete it at 2.2kg (4.85lbs).

Further analysis shows that between 27 July 2020 and 9 February 2021, the NHS 12-week plan was downloaded 864,403 times, with almost 69,000 users signing up to use it. Of these, 8,305 (12%) completed the full 12 weeks.

Analysis by Public Health England found that:

More than three-quarters (77.4%) of starters and more than nine in 10 (84%) completers reported weight loss after using the 12-week plan
The average weight loss for starters was 2.35% (2.1kg) and almost 6.5% (5.8kg) for completers compared to their starting weight
More than a sixth (17.1%) of starters and almost two-thirds (64.2%) of completers experienced weight loss of 5% or more
Almost one in seven (13.2%) of starters and less than one in 20 (4.4%) completers reported a weight gain after using the plan, at an average of 2.2% and 2.9%, respectively

Mean percentage weight change for starters and completers of the NHS weight loss app by gender

Females comprised more than three-quarters (76.1%) of users and reported a slightly smaller average weight loss compared to their male counterparts (-6.35% vs. -6.92%, respectively).

This trend was also observed in those who started the app but did not finish.

Mean percentage weight change for starters and completers of the NHS weight loss app by age

Among those who started the NHS weight loss plan but did not finish, the average reported weight loss tended to increase with age, from 2.16% for those aged 18-29 up to 2.5% for the over-60s.

However, for completers, the opposite was generally true, with 30-39-year-olds recording the highest average weight change (-7.34%) down to -5.77% for users aged 60 and above.

Mean percentage weight change for starters and completers of the NHS weight loss app by BMI

When broken down by BMI groups, those who completed the 12-week plan reported, on average, a weight loss around three times greater than those who started but did not finish.

From the starter population, users with a BMI of 30-34.9 reported the greatest percentage weight change, with an average loss of -2.41% (almost a third more than those in the lowest BMI group).

This trend was also mirrored for those who completed the programme (-6.79% vs. -5.13%, respectively).

Mean percentage weight change for starters and completers of the NHS weight loss app by ethnicity

App users across all ethnic groups reported a weight reduction, regardless of whether they completed the programme. However, the average reported weight loss was at least double for those who finished the plan compared to those who didn’t.

Among starters, those of Chinese ethnicity reported the highest average percentage weight loss (-2.62%). This was around a third (34.4%) greater than those of Bangladeshi origin, who reported the lowest reported average figure.

Black African completers of the plan recorded the greatest percentage weight loss (-6.72%), almost two-fifths (39.1%) greater than those from the Bangladeshi community (-4.83%).

Average weight loss statistics in the UK through diet

For steady weight loss, health guidelines suggest a deficit of 600 calories per day. This means a calorie consumption of around 1,400 per day for women and approximately 1,900 for men. This should result in an average weight loss per week of 0.5-1kg (1-2lb) (although this will vary depending on many factors, such as the amount and type of exercise you do).

Physical activity accounts for about 15-30% of your daily energy expenditure, yet diet and what you consume in terms of food and drink account for 100% of your energy intake. Therefore, your energy balance equation can be significantly affected by what you eat and drink throughout the day.

When it comes to dealing with patients who want to lose weight, the most commonly advised method is to adopt a nutritionally balanced, hypocaloric diet based on a food guide pyramid.

This usually involves:

Consuming at least five servings of fruit/vegetables a day
Opting for wholegrain varieties where possible (e.g. bread, pasta, rice, cereal)
Eating moderate amounts of dairy and meat
Limiting consumption of food that is high in sugar/fat
Considering portion size to establish a recommended amount from each of these food groups

Alternative approaches could be to adopt a meal replacement programme, where individuals seek to consume between 1,200 and 1,500 calories a day.

Studies have shown that the largest amount of weight loss using this method tends to occur in the earlier stages of the programme. One such example documented that women lost on average more weight between three and six months, compared to men, who tend to lose the most weight after three months.

"I frequently support patients exploring various weight management options, from dietary changes to weight loss injections. The question of sustainability—whether through diet or exercise—is crucial for long-term success.

From my experience, exercise alone requires considerable commitment to create meaningful weight loss. Whilst any physical activity is beneficial, patients often find that modest exercise routines don't deliver the dramatic results they're hoping for. Those who commit to more substantial weekly exercise programmes tend to see better outcomes, but maintaining this level of activity long-term can be challenging.

Diet, however, tends to be where we see the most significant impact. What people eat and drink has a much more direct effect on their weight than exercise alone. Creating a sustainable calorie deficit through mindful eating and portion control is often more manageable for busy individuals than finding several hours each week for intensive exercise.

For patients considering weight loss injections, I always emphasise that these medications work best alongside lifestyle modifications. The most successful outcomes combine pharmaceutical support with both dietary awareness and regular physical activity, creating a comprehensive approach to sustainable weight management rather than relying on any single intervention."

Ayesha Bashir (Prescribing pharmacist at Chemist4U)

The future of weight loss in the UK

Around one in five people surveyed by Ipsos felt they would be likely to use weight loss injections in the future if they were provided on the NHS, compared to less than one in 10 who would if they had to pay privately.

The extent to which people in the UK are likely to use weight loss injections in the future

Contrastingly, almost two-thirds of those surveyed felt they were unlikely to use weight loss jabs, even if they were provided on the NHS. More than four in five people also claimed they would be unlikely to use them, especially if they had to pay for them.

The extent to which people in the UK are likely to tell others they were using weight loss injections

Of those who said they’re likely to use weight loss injections in the future, more than half admitted they would be likely to tell others they were using them, compared to less than a quarter who said they wouldn’t.

"In my role as a clinical pharmacist specialising in weight management, I cannot emphasise enough the importance of a comprehensive approach when considering weight loss medications. The safest and most effective pathway begins with a thorough consultation with your GP or a qualified healthcare professional who can assess your individual circumstances, medical history, and potential drug interactions.

Weight loss medications should never be viewed as a standalone solution. The most successful outcomes occur when these treatments are combined with sustainable lifestyle modifications, including a balanced, calorie-controlled diet and regular physical activity tailored to your fitness level. This holistic approach addresses the root causes of weight gain while building healthy habits that support long-term success.

Regular monitoring is essential throughout your weight loss journey. Regular check-ups allow healthcare providers to monitor your progress, adjust dosages if necessary, and identify any adverse effects early. Additionally, incorporating behavioural support, such as counselling or support groups, can address the psychological aspects of weight management.

Sustainable weight loss is a gradual process. Realistic goal-setting and patience are crucial for achieving lasting results whilst maintaining your overall health and wellbeing."

Ian Budd (Prescribing pharmacist at Chemist4U)

A 2024 study published in The Lancet investigated whether weight loss and improved body composition were sustained better after the first year of termination of a GLP-1 agonist (liraglutide), a supervised exercise programme, or both combined for one year.

Their findings show that, after ending the combined approach:

The average reduction in body weight was 5.1kg (-2.3% loss in body fat) compared with the termination of liraglutide alone.
More participants maintained a weight loss of at least 10% of their initial body weight one year after treatment termination compared to those receiving a placebo and liraglutide.

Average weight gain was 6.0kg larger after GLP-1 treatment stopped, compared to the termination of supervised exercise and 2.5kg more for the combined approach.

Estimated approval dates for various weight loss injections (as of May 2025)

GLP-1 agonists have been instrumental in the pharmaceutical market since the FDA approved AstraZeneca’s Byetta in 2005.

Ozmosi suggests that several companies are in the process of developing GLP-1 oral and injectable formulations (see above), which are due to enter the market by 2030 once approved.

Of the 17 weight loss medications anticipated to enter the fray by 2030, more than a quarter (29%) of these are expected to be from Eli Lilly.

Weight loss FAQs

On average, how long does it take to see weight loss results?

It may take between four and eight weeks to start seeing some initial weight loss changes. However, this length of time can vary depending on numerous factors, such as your starting weight, body composition, the type of weight loss plan you’re on, and how consistently you follow it.

How much weight loss is noticeable?

According to the Centers for Disease Control and Prevention (CDC), losing between 5-10% of your body weight starts to make your weight loss noticeable. Therefore, if you weigh 120kg (18st 13lb), you probably need to lose between 6kg (13lb) and 12kg (26lb) before it becomes noticeable. However, if you weigh 70kg (11st), then your target weight loss figures are likely to be between 3.5kg (8lb) and 7kg (15lb).

How much weight is it possible to lose in a month?

The CDC recommend an average weight loss per week of 1-2lbs for a sustainable weight loss rate of 4-8lbs over a month. Those wishing to lose 100lbs or more may be able to shed 20lbs a month, though some of this may be water weight. Rapid weight loss does not necessarily equate to guaranteed, long-term results, as losing weight too quickly can negatively impact your metabolism.

How much weight can you lose in a year?

Following a healthy weight loss rate of 1-2lbs per week, you could expect to lose somewhere between 52-104lbs in a year. This does assume you are consistent with your approach and is dependent on many factors, such as your starting weight, regularity and intensity of exercise, and your diet plan.

How long does a weight plateau last?

A weight plateau could last anything between a few days to several months and can occur at any time during a weight loss programme. According to the Bariatric & Metabolic Center of Colorado, the average weight plateau lasts between eight to 12 weeks, but varies from person to person.

What is the most common cause of unexplained weight loss?

Unintentional weight loss can be caused by many factors, including:

A stressful event (such as losing a job, the death of a loved one, or going through a divorce)
Malnutrition
Underlying health conditions (such as overactive thyroid, type 2 diabetes, and heart failure)
Mental health conditions (such as depression, anxiety, and eating disorders)
Digestive issues (such as coeliac disease or irritable bowel syndrome (IBS))

What is the most common cause of weight loss in the elderly?

Weight loss in the elderly can be caused by many reasons. Some of the most common include:

Social isolation - decreasing appetite triggered by loneliness and a lack of desire to eat properly.
Chronic medical conditions - cancer, Parkinson’s, overactive thyroid, heart disease, and diabetes can negatively impact your appetite and eating habits when you get older.
Negative reaction to medication - side effects include loss of taste, smell, dry mouth, nausea, and vomiting.
Mental illness - conditions such as depression, bipolar disorder, and anxiety can suppress your appetite, particularly in old age. Sufferers of Alzheimer’s disease and dementia may also forget to eat or turn to an unhealthy diet.
Inability to perform activities of daily living (ADLs) - reduced mobility can impact the ability to access proper food and lead to unhealthy food choices.
Natural ageing - muscle atrophy, reduced bone density, and the depletion of liver and kidney cells can negatively impact the body’s ability to digest and absorb key nutrients.

Do obese people lose weight faster?

Obese people have the potential to lose weight faster simply because they have more weight to lose in the first place. Changing your diet could result in a significant calorie deficit, which is likely to lead to a reduced body weight. Once you introduce regular exercise into the equation, the potential for greater weight loss increases further. However, as you start to lose weight, you may find the rate of weight loss tapers off (known as the weight loss plateau) due to changes in your metabolism.

Sources and methodology

Most popular weight loss programmes based on search volumes (exclusive data)

Google Trends data was collected for different weight loss programmes to see which was the most popular in terms of Google searches. It’s worth noting that Google Trends data is measured as an index score out of 100 (as opposed to actual search volumes). So, this represents a relative measure rather than an exact one.

This data was collected between January 2010 and May 2025 to ascertain changing popularity over time.

From this, a ‘shift of interest’ value was calculated for each weight loss programme using the following formula: (sum of Google Trends for June 2024 to May 2025 - sum of Google Trends for June 2023 to May 2024) / sum of Google Trends for June 2023 to May 2024.

This measures how the interest shifted in the last 12 months compared to the previous 12 months.

Forecasts were generated for June 2025 to December 2026 using FORECAST.ETS. This applies exponential smoothing to model seasonality and trends based on historical Google Trends data to project interest levels for the remainder of 2025 and into 2026.

Mounjaro and weight loss jab advice on TikTok (exclusive data)

Top-performing videos were selected across a range of relevant weight-loss jab advice hashtags under the keyword mounjaro advice on TikTok. Examples included: #mounjaro, #mounjaroweightloss, #mounjarotips, #glp1, #tirzepatide and many more.

Videos providing advice, tips, and suggestions about weight loss injections were selected (e.g. things to know when starting, dosage suggestions, injection sites, etc.), including those which could be used to inform viewers' choices (e.g. what I eat in a day).

In total,100 videos were analysed, with each being scrutinised for whether or not:

There were relevant disclaimers
The creator encouraged viewers to do their own research
The creators were selling or pushing something alongside their advice
The video directed viewers to a pharmacy website
The video included a discount code
The video explained how to get hold of jabs
The creator was boasting about their new lifestyle following their weight loss
The video included any information on how to administer the jabs
The video noted how much weight they’ve lost on weight loss jabs

Creators who scored negatively in three categories or more were labelled as giving ‘potentially misleading’ advice. Videos which scored as ‘somewhat’ in a category were included in the ‘yes’ figures for clarity (e.g. if a creator suggested an injection schedule and sites, they were labelled as ‘somewhat’ explaining how to administer weight loss jabs).

Additionally, the creator profile of each video was analysed to collect the following:

Number of followers
Whether they are a male or female creator
Whether or not their account is dedicated to weight loss jabs
Whether or not they feature a discount code in their bio or Linktree
Whether or not they feature a pharmacy website link in their bio or Linktree

Data is correct as of May 2025.

Most popular weight loss injections based on search volumes (exclusive data)

Google Trends data was collected for different weight loss injections to see which was the most popular in terms of Google searches. It’s worth noting that Google Trends data is measured as an index score out of 100 (as opposed to actual search volumes). So, this represents a relative measure rather than an exact one.

This data was collected between January 2010 and May 2025 to ascertain changing popularity over time.

This measures how the interest shifted in the last 12 months compared to the previous 12 months.

Attitudes towards weight loss injections in the media (exclusive data)

Muck Rack was used to extract article-level media coverage for different weight loss injections. This was then processed to find the volume of media coverage per drug and broken down by sentiment. The TextBlob library in Python was used (article title + snippet) to add subjectivity scores to calculate the relative subjectivity (public interest) or objectivity (factual presentation) of these articles.

All Muck Rack articles for a given weight loss injection were studied. In cases where the article count exceeded 10,000, just the first 10,000 articles were analysed.

The number of Unique Visitors per month (UVM) was obtained from Muck Rack data. This is a measure of the potential reach of a publication/outlet (not the individual article). A breakdown of the total UVM for an article by sentiment indicates the degree to which a drug’s media exposure is positive or negative.

Data was collected between May 2020 and May 2025 to see how these trends have changed over time.

Percentage change on the NHS weight loss app

Missing weights occurred when users did not continue to enter data for the full 12-week plan. Public Health England wished to report an ‘intention-to-treat’ analysis on the effectiveness of the 12-week plan across all users who started using the app, so they imputed the missing weight data using two imputation methods:

Last Observation Carried Forward (LOCF)
Baseline Observation Carried Forward (BOCF).

Both LOCF and BOCF were calculated for starters only, as final weights were recorded for those who completed the programme. LOCF is used as the main measure for outcome weight change for all users who started the 12-week plan.

For further details, please consult the Public Health England report.

Average cost of weight loss surgery in the UK

The average starting price of various weight loss surgeries was taken from a number of reputable UK healthcare providers. From here, the average was then taken to ascertain the typical cost of weight loss surgeries in the UK.

Written by: Chemist4U

Updated On: 11 August 2025

Reviewed and fact-checked by: Jason Murphy , Prescriber & Clinical Lead on 11 August 2025

GPhC Number: 2235439

i How we ensure accuracy in our content