Mounjaro

Based on 1719 reviews

Needles are included with your pen.

  • Clinically proven to help you lose up to 22% of your weight
  • Reduces your appetite, regulates blood sugar and helps you feel fuller for longer
  • Safe and effective for long-term weight loss and weight maintenance
  • Delivered in plain, discreet packaging to protect your privacy
  • Always read the patient information leaflet before use
Upon completion of a medical consultation with one of our health care professionals you can expect prices to start from £148.00
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All inclusive price starts from £148.00
This treatment is inclusive of consultation & private prescription
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Alexandra Smith - Senior Medical Writer
Alexandra Smith
Senior Medical Writer
02/10/2025
01/10/2027
Jason Murphy - Head of Pharmacy
Jason Murphy
Head of Pharmacy
2235439
02/10/2025

What is Mounjaro?

Mounjaro is a once-weekly injection designed to support weight loss and help with weight management. It works by reducing cravings, lowering your appetite, and helping you feel fuller for longer, even when you’re eating less.

Mounjaro’s main ingredient is called tirzepatide. It works on two natural hormones in the body: GLP-1 (glucagon-like peptide-1) and GIP (glucose-dependent insulinotropic polypeptide). Most weight loss injections only work on GLP-1, but Mounjaro is different because it works on both. This makes it a “dual agonist” treatment, and research shows it can lead to more weight loss than other options.

Through multiple clinical trials, Mounjaro has been proven safe and effective for long-term use in the UK, and is only available on prescription through licensed providers like Chemist4U.

“Mounjaro works best when paired with lifestyle changes, like eating a balanced diet, staying active, and building healthy habits you can stick with. Combining these with your treatment plan gives you the best chance of seeing results and reaching your weight loss goals safely. At the end of the day, healthy habits support weight loss and help you maintain it for the long term.”

- Jason Murphy, Head Pharmacist

Who manufactures Mounjaro?

Mounjaro is manufactured by Eli Lilly, a pharmaceutical company founded in 1876. For over 145 years, they’ve been trusted to produce medication for diabetes, mental health, cancer, and, more recently, weight loss. In 2022, they launched Mounjaro. Today, their treatments are used by millions of people in more than 100 countries.

How does Mounjaro work?

Mounjaro works in three key ways:

  1. Reducing appetite: Mounjaro works on two hormone receptors (GLP-1 and GIP) to signal your brain that you’re full. This helps curb cravings, control portion sizes, and make following a weight loss plan easier.
  2. Slowing digestion: By slowing how quickly food leaves your stomach, Mounjaro keeps you feeling satisfied for longer, helping you avoid unnecessary snacking and stay on track with healthier eating habits.
  3. Regulating blood sugar: Mounjaro improves insulin response and helps stabilise blood sugar levels, reducing hunger spikes.

All of this helps you stay in a calorie deficit when following an appropriate diet, which is the key to effective and sustainable weight loss. A calorie deficit happens when you consume fewer calories than your body burns, encouraging your body to use stored fat for energy. This leads to weight loss and is considered the cornerstone of most weight loss programs.

How long does it take to work?

Mounjaro starts working from your very first dose, helping reduce your appetite and cravings immediately, and most people notice a real difference within their first week. During this time, you may find that:

  • Your appetite feels reduced
  • Cravings become easier to manage
  • You feel fuller for longer, even with smaller portions

It can take a little longer for some people, who may not experience the full effects for a few weeks.

While Mounjaro starts working immediately, you might not see huge movement on the scales in your first month. More noticeable changes in your weight and appearance happen as you continue treatment.

How effective is Mounjaro?

Mounjaro is highly effective in supporting weight loss. Clinical studies have found that patients taking Mounjaro achieved an average weight loss of around 22% of their body weight over 72 weeks. However, results can vary from person to person.

Factors like your starting weight, commitment to your diet and exercise plan, and any underlying health conditions can all influence your progress. What matters most is that you're taking positive steps to improve your health.

Mounjaro in clinical studies

Mounjaro has undergone rigorous clinical trials, the largest of which were the SURMOUNT trials. These trials tested Mounjaro’s efficacy on thousands of people through randomised, placebo-controlled studies.

The trials and results

Trial

Duration & size

Highest average weight loss

Common side effects

Key takeaway

SURMOUNT-1

72 weeks, 2,539 people

–22.5% (15 mg)

Nausea, diarrhoea, constipation

Up to 57% lost ≥20% of body weight.

SURMOUNT-2

72 weeks, 938 people

–14.7% (15 mg)

Nausea, diarrhoea, vomiting

Strong results in people with type 2 diabetes.

SURMOUNT-3

72 weeks, 806 people

–21.1% (after lifestyle run-in)

Nausea, diarrhoea, constipation

Effective even after a diet and exercise program.

SURMOUNT-4

36 weeks open-label + 52 weeks randomized, ~700 people

–21% (first 36 weeks)

Nausea, diarrhoea, vomiting

Tested weight maintenance. Patients who stayed on Mounjaro kept weight off. Those who stopped regained much of it.

Key Takeaways

  • Across each trial, Mounjaro led to 15–22.5% average weight loss.
  • Most patients (80–90%) achieved at least 5% weight loss.
  • Many reached 20% or more, similar to results from bariatric surgery.
  • Side effects were mostly mild stomach issues like nausea and diarrhoea.
  • SURMOUNT-4 proved long-term benefits: continuing Mounjaro helps keep weight off, while stopping can lead to weight regain.

In summary, these trials showed Mounjaro to be highly effective in weight loss with only mild side effects.

Is Mounjaro right for me?

To find out if Mounjaro is right for you, you’ll need to complete an online consultation. Here, you’ll answer a few short questions about your health so a clinician can check whether it’s right for you before prescribing.

Whether Mounjaro is right for you depends on your current weight, health conditions, medications, and medical history. Your clinician will take all of this into account before prescribing. If it’s not right for you, they’ll work with you to find a suitable alternative treatment and provide advice if you’re concerned about your health and weight.

Mounjaro doses

Mounjaro comes in different dose strengths, and you’ll gradually increase your dose over time. You’ll usually start on 2.5mg and work your way up to a maintenance dose, which can be up to 15mg. This step-by-step process is called ‘titration’. It allows your body to adjust slowly, helping to reduce side effects and keep you safe.

Your maintenance dose is the highest dose of Mounjaro you’ll take, as it’s designed to support the best long-term weight loss for you. For some people, this may be lower than 15mg. Your prescriber will work with you to find the right dose for you.

Mounjaro dosing schedule

A typical Mounjaro dosing schedule looks like this:

Weeks

Dose

How often

What this means

1–4

2.5 mg

Once a week

This is your starting dose. It helps your body get used to Mounjaro.

5–8

5 mg

Once a week

Your first increase, most people tolerate this well.

9–12

7.5 mg

Once a week

Gradually increasing to boost results.

13–16

10 mg

Once a week

By now, many people notice steady weight loss.

17–20

12.5 mg

Once a week

Higher dose if needed for extra support.

21 onwards

15 mg

Once a week

This is the maximum maintenance dose. Not everyone needs to go this high. Your prescriber will decide what’s right for you.

Your dosing schedule might vary depending on how you respond to treatment or whether you experience any side effects.

Weight loss week by week

While everyone’s weight loss journey is different, here’s what you could expect from your first 6 months and beyond on Mounjaro.

Weeks one to four – Getting started

Dose: 2.5mg

  • Your body is adjusting to the medication, so you may notice mild side effects.
  • Appetite and cravings may start to reduce, but significant weight loss is unlikely at this stage.

Weeks four to eight – Appetite control

Dose: 5mg

  • Many people begin noticing fewer cravings, feeling fuller for longer, and finding it easier to manage portion sizes.
  • Energy levels improve as your eating habits become more balanced.

Months three to six – Visible results

Dose: Increased gradually up to 15mg.

  • You have much better appetite control, making it easier to stick to healthy routines and manage “food noise.”
  • Most people notice steady, visible weight loss by this stage — typically 9–11% of body weight by month six.*

Six months+ – Long-term progress

Dose: Maintained at 15mg (or your chosen maintenance dose)

  • By now, most people feel more in control of their eating habits and have better daily energy levels.
  • With healthy lifestyle changes, patients can lose up to 22% of their starting weight after 18 months.

*Results vary between individuals.

Why do you have to increase your dose of Mounjaro?

You need to gradually increase your dose of Mounjaro to give your body time to adjust to the medication. This step is important for your safety, as it helps reduce side effects and ensures your body is responding well to treatment.

Do I need to start from the lowest dose of Mounjaro?

Yes. If you’re new to Mounjaro, you need to start from the lowest dose. This is to make sure you respond well to the medication and to help reduce side effects.

What happens if I miss a dose?

If you’ve forgotten or missed a dose, what you should do depends on how much time has passed since you were meant to take it.

  • If it’s been less than four days, take the dose and continue treatment as normal.
  • If it’s been more than four days, skip the dose and take your next dose on your regular day.
  • If it’s been more than two weeks, speak to your prescriber. You may need to restart or adjust your treatment plan.

Never take more than one dose at once to make up for missing a dose.

When should I order my next dose?

If you’re increasing your dose, we recommend waiting until your third injection before ordering your next dose. This is to ensure that you’re tolerating your current dose before increasing.

While you can order three weeks in advance, if you were to develop side effects during that time, you might not be able to move up to your new dose.

It’s also important to remember to keep any unopened injections you order early in the fridge until you’re ready to take them.

Mounjaro eligibility

Mounjaro is suitable for people who are medically obese or overweight with weight-related health issues and are looking to lose weight. This means having a BMI over 30, or a BMI over 27 with a condition like high cholesterol, high blood pressure, or type 2 diabetes.

How do I get a prescription for Mounjaro?

You can get a prescription for Mounjaro privately through a trusted, regulated provider like Chemist4U. All you need to do is complete a short online consultation so a prescriber can check your eligibility and make sure it’s safe for you. If you’re eligible and they’ve reviewed your health, they’ll issue a prescription.

Can you get Mounjaro on the NHS?

Yes, you can get Mounjaro on the NHS, but the criteria are much stricter, making it more challenging to access than using a private service. 

Their criterion is that you must have a BMI of 40 or more (or 37.5 and above for certain ethnic groups) and at least four weight-related health conditions, such as type 2 diabetes, high blood pressure, heart disease, or sleep apnoea.

In addition, it can only be prescribed through specialist weight management services, which are currently being rolled out in phases across the UK.

Will my GP be informed if I start Mounjaro with Chemist4U?

Yes. When you start treatment, a letter is issued to inform your GP that you have been issued a prescription for Mounjaro. This is to keep any other healthcare professionals involved in your care, and informed of your current medication.

Mounjaro prices

Mounjaro price increases:

As of 1st September, the manufacturer of Mounjaro, Eli Lilly, raised its UK supply prices. This increase affected every provider in the country, meaning that most providers have had to raise their prices to cover the higher costs.

Why did Mounjaro’s price increase?

Mounjaro’s price has recently increased because it has become more expensive for providers to purchase the medication. Eli Lilly raised the UK supply prices by up to 170%, which means providers now must pay significantly more to source Mounjaro and, in turn, have had to increase their prices to cover these higher costs.

Will the price go down?

We can’t confirm whether Mounjaro's price will decrease in the future. This will depend on whether Eli Lilly adjusts its UK supply costs and how individual providers set their own pricing. Since prices have only recently increased, it’s unlikely there will be any significant changes in the short term.

What should I do if I can’t afford Mounjaro?

If you can’t afford your treatment, you may want to consider switching to a more affordable alternative, like Wegovy. Unlike Mounjaro, Wegovy’s price has not changed, making it easier to budget for.

You can safely switch treatments with the support of our clinicians, provided you take a break from Mounjaro before starting Wegovy. Our doctors will guide you through the process, explain your options, and help you make the best decision for your health and budget.

Learn more about the Mounjaro price increases and explore your options if you’re considering making a change.

How much will my weight loss journey cost?

How much your journey with Mounjaro costs will depend on your dosing schedule and maintenance dose, as well as how long you stay on treatment. Here’s an example of what a typical six-month weight loss journey could look like, along with the cost.

Mounjaro monthly costs

Six-month cost on a typical dosing schedule:

Month

Dose

Cost (£)

Cumulative (£)

1

2.5mg

148

148

2

5mg

198

346

3

7.5mg

248

594

4

10mg

278

872

5

12.5mg

298

1170

6

15mg

308

1478

The following 6 months would cost the same monthly, as you would be on your maintenance dose.

How can I save on Mounjaro?

Understanding the costs so you can budget effectively is the best way to save during your treatment. When you know what to expect, it’s easier to plan ahead.

Some patients find they can stay on lower doses if they’re still achieving good results and getting the full benefits of the medication. This can save money in the long term, but only if it continues to work for you. Learn more about funding your weight loss treatment.

How often do I need to do a consultation?

You need to complete a consultation each time you request treatment. However, repeat consultations take less time to complete, and you won’t need to submit new photos each time.

Can I switch medication?

Yes. You can switch to a different medication if a clinician approves it and thinks it’s safe for you to do so. In most cases, you’ll need to stop your current medication and wait for it to leave your system before starting your new treatment.

What’s included with my treatment?

With your first delivery, you’ll receive:

  • Mounjaro pen (pre-filled with your required dose)
  • Single use needles
  • Sharps bin (if it’s your first order)
  • Patient information leaflet
  • Welcome pamphlet (including complete instructions on taking your treatment)

You’re entitled to free ongoing support from our clinicians who can provide advice during your journey at no extra cost.

We’ll also provide regular updates, reorder reminders, and online guides to help you get the most out of your weight loss package.

Do I need to buy my own needles?

You do not need to buy your own needles, as these are provided with your treatment.

How do I take Mounjaro?

You take Mounjaro as an injection once a week. You can either do this yourself or have someone help you. The pens are designed to be as straightforward as possible, and you’ll be given full advice and instructions on administering your treatment.

We also provide complete guidance on exactly how to take Mounjaro.

Best injection sites for Mounjaro

Recent trials suggest that where you inject Mounjaro may affect both the side effects you experience and, in some cases, how much it suppresses your appetite. However, the strength of your dose remains the same regardless of the injection site.

Side effect rates by injection site:

  • Abdomen: 68.52%
  • Upper arm: 57.41%
  • Thigh: 43.40%

Appetite suppression by injection site:

  • Abdomen: 24.07%
  • Upper arm: 12.96%
  • Thigh: 5.66%

If weight management is your main goal, injecting into the abdomen may offer stronger appetite suppression, but it could also come with a higher chance of side effects.

Does it matter if there’s an air bubble in the pen?

Small air bubbles can appear in pens. These are typically harmless and nothing to worry about.

Mounjaro side effects

More than 10% of people experience the most common side effects of taking Mounjaro. This usually happens when first starting treatment and increasing the dose. These side effects are usually gastrointestinal (affecting the digestive system) and can be managed at home with over-the-counter treatments or lifestyle changes.

Most of these side effects are usually mild and go away on their own as your body gets used to treatment. But if you’re finding them too difficult to manage or they’re getting worse, you should speak to your clinician.

Serious side effects

Less common but more serious side effects can include:

  • Pancreatitis
  • Gallbladder problems
  • Allergic reactions

These side effects are extremely rare, but if you experience any symptoms of these, stop taking Mounjaro and seek medical help immediately.

Injection site reactions:

Injection site reactions are a common side effect of Mounjaro. They usually appear as rashes, bruising, or swelling where you’ve been injecting. You can reduce this by changing injection sites regularly and making sure your injection sites are clean.

If you’re concerned about needles containing nickel, our needles only contain trace amounts, which you are not exposed to while injecting. There is no residue left behind that contains nickel.

How long do side effects last, and are there long-term side effects?

Most common side effects of Mounjaro settle down or go away within a few days or weeks as your body adjusts to the medication. However, everyone’s experience is different, so this isn’t always the case. Side effects can also return or start when changing dose.

If side effects don’t go away or worsen, it’s important to speak to your prescriber.

While more data is needed to say for sure, there are currently no reported long-term side effects caused directly by taking Mounjaro.

Ways to prevent side effects

The best ways to prevent side effects when taking Mounjaro are to stay hydrated, eat small, regular meals, and stick to a bland diet (especially if you’re concerned about stomach issues). It’s also important to follow your dosing schedule and pace yourself. If you experience side effects, you don’t need to increase your dose straight away.

You can also take over-the-counter treatments to help, like antacids or laxatives.

What happens if I lose weight too quickly?

Losing weight too quickly can lead to muscle loss, excess skin, a slower metabolism, and nutrient deficiencies. It can also increase the risk of side effects like gallstones, fatigue, and dehydration. On top of that, it may negatively affect your mental health, leading to anxiety and stress.

Rapid weight loss can also make it harder to maintain your results, especially after coming off treatment.

That’s why we support you in building a plan that promotes safe, sustainable weight loss at a pace you can maintain.

The benefits of losing weight

Losing weight doesn’t just change how you look; it also changes how you feel and improves your health. It improves your health by:

  • Lowering risk of heart disease and stroke
  • Improving blood pressure and cholesterol levels
  • Reducing the risk of type 2 diabetes or helps manage it
  • Decreasing joint pain and improving mobility
  • Supporting better sleep and lowering the risk of sleep apnoea
  • Boosting energy levels and stamina
  • Enhancing mental health and reducing stress on the body

It also leads to:

  • Increased confidence
  • Higher energy levels
  • Better mobility and physical comfort
  • Improved mood
  • Better sleep

Learn more about how weight loss injections improve your health beyond weight loss.

Is Mounjaro safe?

Yes. Mounjaro has been through multiple clinical trials and reviews to make sure it’s safe for use. It’s also been approved by regulatory authorities like the MHRA.

Is Mounjaro safe for non-diabetics?

Mounjaro is safe for non-diabetics. As long as you have a BMI over 30, or over 27 with a weight-related health condition, it can be prescribed whether you have diabetes or not.

Who can’t take Mounjaro?

Like all medications, Mounjaro isn’t suitable for everyone. If you don’t meet the criteria for it, or you’re allergic to any of its ingredients, it won’t be safe for you.

It’s also not suitable for people with certain health conditions, like:

  • a personal or family history of thyroid cancer
  • a history of pancreatitis
  • a history of diabetic retinopathy

Finally, you can’t take Mounjaro if you’re pregnant, trying to conceive or breastfeeding. If you unintentionally get pregnant while taking Mounjaro for weight loss, you should stop treatment and speak to a doctor.

Storage, diet & lifestyle

How do I store Mounjaro, and can I travel with it?

Mounjaro must be refrigerated until you’re ready to take it. If it gets too hot or freezes, you need to dispose of it. Once you’ve used a pen, it can be kept at room temperature for up to 30 days.

  • You can travel with Mounjaro. However, you need to ensure it’s kept at the right temperature. Because of this, you need to travel with it as carry-on luggage, as there can be temperature fluctuations in the hold.
  • If it hasn’t been opened yet, keep it in a cooler bag between 2°C and 8°C.
  • If it has been opened, you can store it at room temperature while travelling.

It’s also important to check the rules for travelling with medication at your destination, so you know whether you’re allowed to take it with you and how much you can carry.

Do I need to change my diet while on Mounjaro?

Yes. It’s important to follow a proper diet while taking Mounjaro. While the medication helps suppress your appetite, without healthy eating, it won’t work as effectively, and you may not see the same results.

Certain foods and drinks can make different side effects worse or more likely.

We can help you understand how to diet on Mounjaro to get the most out of your treatment.

Can I still drink alcohol?

You can drink alcohol while on Mounjaro, but it’s not recommended. While alcohol doesn’t directly interact with Mounjaro, it can make some side effects worse, like dehydration and diarrhoea.

If you do choose to drink, try to do so in moderation and avoid drinking too often.

Exercise and Mounjaro

Exercise is important when taking Mounjaro. It can help ease side effects like constipation, boost weight loss, and support muscle growth while you lose weight.

That doesn’t mean you need to start running marathons or hitting the gym every day; you can start small and build up gradually. Even adding a little more movement to your daily routine can make a big difference.

Try:

  • taking short walks after meals
  • using the stairs instead of the lift
  • doing light stretching or yoga at home
  • adding small strength exercises like squats or push-ups

Can Mounjaro cause muscle loss?

Any form of weight loss can lead to muscle loss, and losing weight with Mounjaro is no different. One study showed that patients on Mounjaro had a 10.9% reduction in lean mass, as well as weight loss. This means that muscle loss can happen, especially if you’re not taking the right steps to prevent it.

Here’s how our clinicians can help you to prevent muscle loss on Mounjaro.

Should I take supplements on Mounjaro?

You can take supplements on Mounjaro if you need to, but it’s best to check with your prescriber before taking them.

With the right diet, you should be able to get all the nutrients you need. However, if you’re worried about deficiencies or if treatment is making it harder to get the nutrition you need, there are supplements you can take safely.

Delivery FAQS

When you are prescribed Mounjaro from Chemist4U, we deliver your treatment to your door. We make this quick and discreet to ensure you have your treatments when you need them and that your privacy is protected.

How long does delivery take, and do I need to be home to take delivery?

Weight loss treatments are usually delivered the next working day or the day after, depending on the time you order. You will need to be home to receive yourdelivery.

Weight loss medication is always sent via Royal Mail Temperature Controlled Delivery which takes between 24 and 48 hours. You will be given full tracking information and a delivery window, so you know when to be home.

Patient testimonials: Before and after results

Looking at before-and-after results from patients on Mounjaro can help you understand just how effective it can be.

Take Baylee’s story, for example. She lost over nine stone in just seven months, going from 20 stone to 11 stone:

“Mounjaro has been amazing. I’ve had minimal side effects, and it’s been a lifesaver for the symptoms of my pre-existing medical conditions. I’d recommend this to anyone who’s struggling to lose weight.”

Everyone’s journey on Mounjaro is different, and results vary from person to person. Hearing success stories like Baylee’s can give you a better idea of what treatment could look like for you.

See more of our before and afters from patients hitting their goals with Mounjaro.

Alternative treatments:

Mounjaro isn’t the only weight loss treatment available. Alternatives come in injection, tablet and capsule form, and their effectiveness can vary.

Tablet treatments

Orlistat (also known as Xenical or Alli): This treatment works differently from Mounjaro. Instead of helping you feel full, it reduces the amount of fat your body absorbs from food. The unabsorbed fat then leaves your body as waste.

Mysimba: This treatment acts on areas of the brain that control appetite and cravings, helping you eat less and reduce snacking.

Injectable treatments

Wegovy: A weekly injection similar to Mounjaro, Wegovy helps you feel full after smaller meals. On average, patients achieve around 15–17% weight loss.

Saxenda: This is a daily injection that works similarly to Wegovy and Mounjaro, but with a lower average weight loss of around 8–10%.

New weight loss treatments are in development and expected to become available in the coming years, offering patients even more choice.

Learn more about our alternative treatments to Mounjaro

Wegovy or Mounjaro, which is best?

Mounjaro is considered the most effective treatment, as it has been proven to achieve the best weight loss results. However, this doesn’t mean it’s the best weight loss treatment for you.

Feature

Mounjaro

Wegovy

Active ingredient

Tirzepatide

Semaglutide

How it works

Dual action: targets GIP and GLP-1 receptors to regulate blood sugar and appetite

Targets GLP-1 receptors to regulate appetite and blood sugar

Dosing

Weekly injection, starting at 2.5 mg and gradually increased up to 15 mg

Weekly injection, starting at 0.25 mg and gradually increased up to 2.4 mg

Weight loss potential

Clinical trials (72 weeks) showed an average loss of up to ~22% of body weight.

Clinical trials (68 weeks) showed an average loss of up to ~17% of body weight.

Appetite suppression

Generally stronger due to a dual-action mechanism

Strong, but typically less effective than Mounjaro

Common side effects

Nausea, diarrhoea, constipation, tiredness, risk may be slightly higher due to dual action.

Nausea, diarrhoea, constipation, tiredness

You may find that your body responds better to either Mounjaro or Wegovy, or that one causes fewer side effects, making your weight loss journey smoother. It’s also worth considering your budget. Since these are long-term treatments, choosing an option that works for your health and your wallet is important.

Frequently asked questions

What is the golden dose (5th dose)?

Some people refer to the “golden dose” or “5th dose” of Mounjaro when talking about the small amount of liquid left in the pen after you’ve taken your four prescribed doses.

However, this leftover liquid is not intended to be injected or used. It’s there to prime the injector and make sure your doses are delivered correctly, not to provide an extra dose.

Some people inject this remaining liquid, thinking they can stretch their treatment and save money, but this can be dangerous. The leftover liquid isn’t designed to be used, and there’s no way of knowing how much you’re taking. Injecting it can lead to more side effects, including nausea, vomiting, diarrhoea, and constipation. It can also lead to underdosing, which can hinder your progress and slow down your weight loss journey.

For your safety, only use Mounjaro exactly as prescribed and speak to your clinician if you have concerns about costs or dosing.

From 2026, Mounjaro will be provided in new pens with minimal liquid left over after completing your doses.

I’m scared of needles. Do I have to inject it?

Mounjaro is only available as an injection. However, there are weight loss tablets available. Some work similarly to Mounjaro, like Orlistat, and others, like Mysimba, work differently by changing how your body absorbs fats.

Should I hide that I take Mounjaro?

If you’re not comfortable telling others that you’re on Mounjaro, you don’t have to. But remember, there’s nothing to be ashamed of. You’re taking positive steps to improve your health and lifestyle with a treatment that’s clinically proven and supported by doctors and the NHS.

Do I need to stop taking Mounjaro when I reach my goal?

You don’t need to stop taking Mounjaro once you reach your goal weight. It can be continued as part of a weight maintenance plan, as long as your prescriber monitors your progress and agrees it’s right for you.

Why am I not losing weight on Mounjaro?

There are several reasons why you might not be losing weight as expected while taking Mounjaro:

  1. You’re not in a calorie deficit

Mounjaro works by helping control your appetite and making you feel fuller for longer, but weight loss still depends on consistently eating fewer calories than you burn. If you’re not on the right diet plan and your food portions, snacking habits, or overall calorie intake haven’t changed enough, you may not see much progress.

  1. You’ve hit a weight loss plateau

Plateaus are very common during any weight loss journey. After the initial stages, your body can adapt to its new lower weight and burn fewer calories than before. This can make progress slower, even if you’re sticking to your plan.

  1. You may need a dose change

Mounjaro is started at a low dose and gradually increased to help your body adjust and reduce side effects. Some people find that they don’t see their best results until they’re on a higher dose.

  1. You might need an alternative treatment

Everyone responds differently to weight loss medications. If Mounjaro isn’t working as well for you, your clinician may suggest exploring other treatment options.

If your weight loss has slowed or stopped, it’s best to speak to your healthcare provider. They can review your progress, check your dose, and help you decide on the best next steps to get you back on track.

 

Does Mounjaro work for everyone?

Mounjaro works for most people, but its effectiveness can vary from person to person. The medication itself is designed to work in the same way for everyone, so there’s generally no reason it wouldn’t work from a medical or ingredients point of view, unless you can’t tolerate it or have a medical reason why it isn’t suitable for you.

However, the amount of weight you lose depends on several factors, including how your body responds, your diet, activity levels, and any other health conditions. Some people may lose a significant amount of weight, while others see more gradual progress or need to find another treatment that works better for them.

How long do I need to stay on Mounjaro?

You can stay on Mounjaro for as long as you need to, if your prescriber thinks it’s safe and suitable for you to do so. Some people choose to discontinue treatment once they reach their goal weight, while others request to stay on it long-term as part of a weight management plan.

You can safely stay on a maintenance dose long term to help keep the weight off.

How quickly does Mounjaro suppress appetite?

Some people start to feel appetite suppression within a day or two of beginning treatment, while for others it may take a couple of weeks. Appetite suppression often increases as your dose goes up, so you may notice stronger effects further into treatment.

Does Mounjaro affect fertility?

There’s no evidence that Mounjaro (tirzepatide) directly affects fertility. In some cases, it may even improve fertility by helping with weight loss and metabolic health.

Mounjaro can reduce the effectiveness of hormonal contraception and isn’t recommended during pregnancy. If you’re planning to conceive or want advice on contraception, speak to your healthcare provider.

Does Mounjaro affect periods?

Mounjaro can sometimes affect your periods. Losing weight and improving how your body handles insulin may make cycles more regular, especially if you have PCOS. Some people may also notice lighter, heavier, or irregular periods when starting treatment. If your periods change a lot or you’re worried, talk to your healthcare provider.

When is the best time to take Mounjaro?

The best time to take Mounjaro is whichever time and day you can stick to each week. Most people choose a time that’s easy to remember or fits their routine. What matters most is taking it on the same day and time each week to help keep your weight loss on track.

Will I gain weight after stopping Mounjaro?

It’s common to regain some weight after stopping Mounjaro, but how much depends on factors like your diet, exercise habits, and overall lifestyle.

Fortunately, because Mounjaro is approved for long-term use, you can continue taking it to help maintain your results. If you decide to stop and notice weight gain, you can speak to your clinician about restarting treatment.

What BMI do I need to start Mounjaro?

To be eligible for Mounjaro, you must have a BMI of at least 30 or above or a BMI of 27+ and a weight-related health condition like type 2 diabetes, high cholesterol, or high blood pressure.

What happens when you stop taking Mounjaro?

When you stop taking Mounjaro, its effects gradually wear off as the medication leaves your body. This can lead to increased hunger and potential weight gain, especially if you’re not sticking to healthy habits and lifestyle changes. Its other positive effects, like helping regulate blood sugar and slowing digestion, will also be reduced, which may make you feel less full than before.

While there are no typical withdrawal symptoms when stopping Mounjaro, there can still be a psychological impact, and you may notice changes in your eating habits.

 

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Mounjaro Reviews

white-star white-star white-star white-star white-star
By Mr Penticost,
October 14, 2025
Next stage of my weight loss journey
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By John Wreaves,
October 14, 2025
It’s an injection that comes pen format and helps you lose weight
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By MRS MARY LANCASTER,
October 14, 2025
Such a break through for people who have suffered with weight issues for numerous years.
white-star white-star white-star white-star
By Mr Hunt,
October 14, 2025
Have not started using this 10mg yet, but delivered quickly
white-star white-star white-star white-star
By MISS C MCDONALD,
October 14, 2025
It's so easy to use and can still eat my meals but don't even think about treats now.

Advice & Guides

Switching from Mounjaro to Wegovy 

You can switch from Mounjaro to Wegovy if your pharmacist thinks it’s safe and suitable for you.  You will usually need to wait at least seven days between your last dose of Mounjaro and your first dose of Wegovy. You will also need to adjust your dosage depending on what dose...
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UK Weight Loss Statistics

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...
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Mounjaro side effects and how to treat them

Around 1 in 10 people get the most common Mounjaro side effects, like nausea, vomiting, or constipation. These usually happen when you first start treatment or increase your dose, as your body gets used to the medication. The good news? They’re typically mild and can often be managed easily at...
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Mounjaro vs Wegovy: What’s the difference and which one’s right for you? 

Wegovy and Mounjaro are very similar treatments. They’re both once-weekly injections that help you lose weight and maintain your results. However, there are some differences between them, such as price, active ingredient, and available doses. Here, we’ll give you everything you need to know about Wegovy and Mounjaro so you...
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Mounjaro price increases: Everything you need to know

Eli Lilly, the manufacturer of Mounjaro, has announced that prices will rise from the 1st of September 2025. They have stated that this is to bring UK prices in line with those in European countries. Here, we’ll explain how and why prices for Mounjaro are changing, and what this means...
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Wegovy and Mounjaro benefits beyond weight loss

Wegovy and Mounjaro are widely known for helping patients lose weight, but their advantages go beyond just shedding pounds. These medications may also improve health in other ways, such as cardiovascular health. Whether you're considering these treatments or already using them, this guide will help you discover their full range...
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The Mounjaro dosing schedule and titration calendar

Considering Mounjaro to support your weight loss journey? You might be wondering about the suitable dosage, given that Mounjaro Injectable pens are available in six different strengths. Determining the right one for you and understanding the concept of titration can seem daunting, but we're here to simplify it in this...
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Everything you need to know about Mounjaro 5mg

If you're looking for support with weight loss and have heard about weekly injection treatments, you may have come across Mounjaro 5mg—a weekly injection gaining attention for supporting weight loss in people living with obesity or type 2 diabetes.  This comprehensive guide explains how Mounjaro 5mg works, what the typical...
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Getting Mounjaro in the UK

Do the NHS prescribe Mounjaro?

The NHS currently has limited availability of Mounjaro. Since March 2025, it’s been mainly prescribed through specialist NHS weight management services for people with a high enough BMI (between 32.5 and 35, depending on their ethnic background) or specific medical conditions. This is due to some ethnicities being at a higher risk of weight-related complications. 

Most people access weight loss injections through private prescriptions from regulated online pharmacies like ours, where you can complete an online consultation with a UK-based prescriber.

Can you buy Mounjaro in the UK?

Yes, Mounjaro is available in the UK through a private prescription. You'll need to complete an online consultation with a qualified prescriber who will assess your suitability. It's not available over-the-counter and must always be prescribed by a healthcare professional.

Can I get Mounjaro from my GP?

Since June 2025, GP surgeries can prescribe Mounjaro to patients at the highest risk. For example, they must have a BMI of 40 and at least four weight-related health conditions. That’s why many people find it easier to access it through regulated online pharmacies specialising in weight management treatments.

How much does a Mounjaro pen cost?

Mounjaro pens cost upwards of £139 for a 4-week supply, depending on the dose strength. Each pen contains four weekly doses, so you'll need one pen per month to maintain your treatment.

How Mounjaro works

What does Mounjaro do in your body?

Mounjaro mimics two natural hormones in your body - GLP-1 and GIP - which help control appetite and blood sugar levels. It makes you feel fuller for longer, reduces hunger, and slows down how quickly food leaves your stomach, so you naturally eat less. This dual action makes it particularly effective for weight loss.

Can I take Mounjaro if I'm not diabetic?

Yes, Mounjaro is approved for weight loss in adults without diabetes. You need a BMI of 30 or above, or 27 and above with a weight-related health condition like high blood pressure or high cholesterol. It's designed specifically to help with weight management, not just diabetes control.

Who can and cannot use Mounjaro

Who cannot take Mounjaro?

You cannot use Mounjaro if you're allergic to tirzepatide or any other ingredients, under 18 years old, pregnant or breastfeeding, or over 75 years old (due to increased risk of side effects). Always inform your prescriber about any medications you're taking, as some may interact with your treatment.

Can I take Mounjaro forever?

Many people use Mounjaro as a long-term treatment to maintain their weight loss. Clinical studies show that people who continued taking it for three years maintained significant weight loss. However, the length of treatment should always be discussed with your prescriber based on your individual needs and health goals.

How long do you stay on Mounjaro?

The duration varies for each person. Some people use it for several months to reach their weight loss goals, while others continue long-term to maintain their results. Your prescriber will regularly review your progress and help determine the best treatment plan for you.

Using Mounjaro safely

Can you drink alcohol on Mounjaro?

It's best to limit or avoid alcohol in your diet while taking Mounjaro. Alcohol can increase side effects like nausea and may reduce how well the medication works. Plus, alcohol is high in calories and can slow your weight loss progress.

What happens when you stop taking Mounjaro?

When you stop taking Mounjaro, you may gradually regain some weight as your appetite and hunger signals return to previous levels. This is why many people choose to continue the treatment long-term or work with their prescriber to develop a maintenance plan.

Can I stay on 2.5mg Mounjaro for weight loss?

The 2.5mg dose is designed as a starter dose to help your body adjust to the medication. While some people may see results at this dose, most people need to increase to higher doses (typically 5mg, 10mg, or 15mg) for significant weight loss. Your prescriber will guide you on the right dose for your needs.

Storage and travel

Can I take my Mounjaro on a plane?

Yes, you can travel with Mounjaro. Keep it in your carry-on luggage (not checked baggage) and bring a prescription letter from your prescriber. If you're travelling to hot climates, use a cooling case to keep it at the right temperature.

What happens if Mounjaro gets hot?

If Mounjaro gets too hot (above 30°C), it may become less effective. Don't use it if it's been exposed to high temperatures for extended periods. Always store it in the fridge before first use, and keep it cool during travel.

What happens when Mounjaro freezes?

Never use Mounjaro if it's frozen. Freezing can damage the medication, making it ineffective or potentially harmful. If your pen has frozen, dispose of it safely and get a replacement.

Using your Mounjaro pen

What happens if you inject Mounjaro in the wrong place?

Mounjaro should be injected into fatty tissue under the skin on your stomach (at least 5cm from your belly button), thigh, or back of your upper arm. If you accidentally inject into muscle, you may experience more pain, but it won't harm you. Just use the correct injection site next time.

Should there be a bubble in my Mounjaro pen?

Small air bubbles are normal and won't affect your dose. However, if you see large bubbles or the liquid looks cloudy, don't use the pen. Contact your pharmacist for advice.

Can I use the leftover Mounjaro in the pen?

No, never try to extract extra doses from your pen. The "leftover" liquid is there to ensure proper priming and consistent dosing. Using it could mean injecting expired medication or getting an incorrect dose, which could be dangerous.

Why is there so much Mounjaro left in my pen after four doses?

This is completely normal. The extra liquid ensures there's enough medication for proper priming and consistent dosing. It's not intended as an additional dose, so always dispose of your pen after four doses, even if liquid remains.

Disposal and waste

What to do with unused Mounjaro?

Return unused pens to your local pharmacy for safe disposal. Don't throw them in household waste or flush them down the toilet. Always remove the needle first and dispose of it in a sharps bin.

Can I return unopened Mounjaro?

Most pharmacies cannot accept returns of prescription medications, even if unopened, due to safety regulations. Check with your specific pharmacy about their return policy, but generally, unused medications should be disposed of safely rather than returned.

What happens if you use expired Mounjaro?

Using expired Mounjaro may be less effective and could potentially be harmful. Always check the expiry date before use and dispose of any expired pens safely at your local pharmacy. Never use medication past its expiry date.

Common concerns

Why do I feel cold while taking Mounjaro?

Feeling cold can be a side effect of rapid weight loss rather than the medication itself. As you lose weight, your body has less insulation, and your metabolism may slow slightly. This usually improves as your body adjusts. If you're concerned, speak to your prescriber.

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