Dexcom ONE+ Sensor - 3-Pack

What is Dexcom ONE+?

The Dexcom ONE+ is a wearable continuous glucose monitoring (CGM) system that measures glucose levels in real time and sends readings directly to your smartphone.

It features an all-in-one sensor with simple one-push insertion and optional alerts for abnormally high or low glucose levels specific to your body.

Unlike traditional finger-prick diabetes testing, which provides a single reading, Dexcom offers ongoing glucose updates throughout the day and night.

According to the NHS, regular blood glucose monitoring is essential in diabetes management to help prevent complications like heart disease, kidney disease, and nerve damage.

Please note that the manufacturer is unable to replace sensors that have been purchased for use on animals. This is because they are not licensed for this use.

Key features of Dexcom ONE+

• Small & discreet: The sensor is worn on the body.
• No fingersticks: All-in-one applicator with one-push insertion.
• Real-time glucose readings: Sent automatically to your phone every five minutes.
• Customisable alerts: High and low glucose alerts outside of a pre-determined range.
• Up to 10-day wear per sensor.
• Integrated design: No separate Dexcom transmitter required.
• Detailed data logging: Allows for logging of food, exercise, and insulin dosage.

Medical devices sold in the UK are regulated by the Medicines and Healthcare products Regulatory Agency (MHRA), ensuring safety and quality standards are met.

What is Dexcom ONE+ continuous glucose monitoring used for?

Dexcom ONE+ is used to continuously monitor glucose levels in people with diabetes, helping to identify trends and reduce episodes of high (hyperglycaemia) and low (hypoglycaemia) blood sugar.

Continuous glucose monitoring can:

• help adjust insulin dosing
• identify patterns linked to meals, stress or exercise
• detect overnight hypoglycaemia
• improve the time your blood sugar spends in its target range (‘time in range’)

Continuous glucose monitoring is recommended for many people with type 1 diabetes and for some individuals with insulin-treated type 2 diabetes, particularly where low blood sugar is a problem.

For more support on managing your condition, read our guide on creating a diabetes diet.

How does Dexcom ONE+ work?

Unlike traditional fingerprick devices (which measure blood glucose levels), Dexcom ONE+ measures glucose levels in the fluid just beneath your skin.

It does this using a small sensor on your skin and a tiny sensor fibre just beneath your skin. It updates readings and sends these automatically to your smartphone or receiver.

The sensor takes glucose measurements frequently and updates the app (approximately every 5 minutes), providing near real-time data.

A short warm-up period (approximately 30 minutes, depending on manufacturer guidance) is required before readings begin.

Unlike traditional glucose meters, which measure capillary blood glucose, CGMs like Dexcom tracks trends over time. This trend data can help you make informed decisions about your insulin, food intake and activity levels.

For your sensor to work, however, it’ll need to be paired with a compatible smartphone or device.

Find out if your device is Dexcom ONE+ compatible.

Who can use Dexcom ONE+ CGM?

Dexcom ONE+ is designed for people who:

• are aged two years and over
• have medically diagnosed diabetes
• need regular glucose monitoring.

It is not intended for individuals without a confirmed diagnosis.

It may be suitable for:

• people with type 1 diabetes
• people with insulin-treated type 2 diabetes
• individuals experiencing frequent lower blood sugar (hypoglycaemia)
• pregnant women with diabetes (under specialist advice)

Always consult your GP or diabetes specialist before starting any CGM system.

How to use Dexcom ONE+

Dexcom ONE+ is typically worn on the back of the upper arm (or other approved site, depending on your age and manufacturer guidance) and lasts up to 10 days.

To use your Dexcom ONE+ sensor correctly:

1. Wash and dry your hands thoroughly.

1. Clean the application site with an alcohol wipe and allow it to dry.

1. Remove the applicator cap.

1. Place firmly against the back of your upper arm.

1. Press the button to insert the sensor.

1. Open the Dexcom app and follow the instructions to start the sensor.

1. Wait for the warm-up period to complete (typically 30 minutes)

The insertion needle automatically withdraws after application, while the sensor filament remains just under the skin.

If the sensor becomes painful, loose or detached, remove it and seek advice from your clinician.

Where can I buy Dexcom ONE+ in the UK?

Dexcom ONE+ is available to buy online in the UK from regulated pharmacies like Chemist4U. While it’s not classified as a prescription-only medicine but is only intended for people with diagnosed diabetes. We’ll ask you a few questions before purchase to make sure it’s right for you.

What’s included in the box?

• one Dexcom ONE+ all-in-one sensor
• built-in transmitter
• applicator device
• instructions for use

Dexcom price

Dexcom ONE+ price varies depending on supplier and whether purchased privately or through the NHS.

With Chemist4U, the price of a Dexcom ONE+ sensor starts from £34.99.

NHS prescription availability

If you meet the eligibility criteria, Dexcom devices may be available on NHS prescription.

Speak to your diabetes team for assessment.

How long will it take Dexcom ONE+ CGM to take readings?

Dexcom ONE+ begins providing glucose data after a short warm-up period, roughly around 30 minutes. It then updates readings automatically at frequent intervals throughout the day and night.

Differences between Dexcom ONE+ and Freestyle Libre 3 Plus

Both systems are effective CGM options. What you choose can depend on personal preference, price, NHS availability and compatibility.

Potential side effects of Dexcom ONE+

Most users tolerate Dexcom ONE+ well, but mild skin reactions may occur.

Possible side effects

• redness
• itching
• swelling at the insertion site
• mild discomfort

Seek urgent medical help if you experience:

• severe allergic reaction (swelling of face or throat, difficulty breathing)
• severe hypoglycaemia (confusion, seizures, unconsciousness)
• persistent high glucose with vomiting or abdominal pain (possible diabetic ketoacidosis in type 1 diabetes)

Dexcom ONE+ storage guidance

Store sensors at room temperature, away from excessive heat or moisture.

Do not use after the expiry date. Keep out of reach of children. Always follow the manufacturer's instructions included in the packaging.

Frequently asked questions about Dexcom ONE+

How do I remove Dexcom ONE+?

To remove your Dexcom ONE+ sensor, gently peel back the adhesive edge and slowly remove the sensor. Clean the skin with warm water and mild soap.

How do I connect Dexcom to a new phone?

To connect your sensor to a new phone, download the Dexcom app on your new device, log in, enable Bluetooth and follow the in-app pairing instructions.

Where can I buy Dexcom ONE+?

You can buy Dexcom ONE+ from UK-registered pharmacies online, including Chemist4U.

Is Dexcom ONE+ waterproof?

Dexcom ONE+ is water-resistant and can usually be worn while showering or swimming, within the manufacturer's depth and time limits.

Can Dexcom ONE+ go through X-ray?

Follow manufacturer and airport security guidance. Sensors may need to be protected during certain imaging procedures.

Can I swim with Dexcom ONE+?

Yes, you can swim with Dexcom ONE+, within approved water-resistance guidelines. Avoid prolonged submersion beyond manufacturer recommendations.

Does Dexcom need WiFi?

No. Dexcom transmits data via Bluetooth. WiFi may be required for app downloads or data sharing.

Does Dexcom pierce the skin?

Yes. A small sterile filament is inserted just beneath the skin to measure glucose in interstitial fluid.

How long does the Dexcom ONE+ sensor last?

Each Dexcom ONE+ sensor lasts up to 10 days before needing replacement.

What’s the battery life of Dexcom ONE?

The battery is built into the sensor and lasts for the full 10-day wear period.

How often does Dexcom ONE+ update?

Dexcom provides frequent automatic glucose updates throughout the day and night.

Can Dexcom ONE+ go through airport security?

You should inform airport security staff that you are wearing a medical device and follow manufacturer guidance.

Can I put Dexcom on my leg, thigh or stomach?

Approved insertion sites depend on age and manufacturer guidance. The back of the upper arm is commonly recommended in the UK.

What devices is Dexcom compatible with?

Dexcom ONE+ connects to compatible iOS and Android smartphones via the Dexcom app. Bluetooth must be enabled, and your device must meet Dexcom’s compatibility requirements.

You should check Dexcom UK’s official compatibility list before purchasing to confirm your device is supported.

What if I need more information?

Thinking about whether Dexcom ONE+ is right for you? Still want more information? Our experts at Chemist4U are available to help answer any questions you might have. Get in touch!

Sources

• Diabetes. (2023). NHS. [Accessed 10 March 2026].
• Hypoglycaemia (low blood sugar). (2023) . NHS. [Accessed 10 March 2026].
• Type 1 diabetes in adults: diagnosis and management. (2022). NICE. [Accessed 10 March 2026].
• Type 2 diabetes in adults: management. (2022). [Accessed 10 March 2026].