Weight Loss Injections in the UK: What They Are and How to Track Them

Several prescription injectable medicines are used for weight management. The most widely discussed in the UK and internationally include:

• Wegovy (semaglutide) — a GLP-1 receptor agonist given as a once-weekly injection. Semaglutide acts on appetite-regulating pathways in the brain, and many people experience a reduced sense of hunger and lower "food noise" while taking it.
• Mounjaro (tirzepatide) — a dual GIP and GLP-1 receptor agonist, also given once weekly. It works on two appetite-related hormone pathways. Like Wegovy, it is prescription-only and subject to additional monitoring (indicated by the black triangle ▼ in its product information).
• Saxenda (liraglutide) — an earlier GLP-1 receptor agonist given as a daily injection. It shares a similar mechanism but is administered differently.
• Ozempic (semaglutide) — the same active substance as Wegovy but licensed primarily for type 2 diabetes management; it is sometimes discussed in the context of weight loss, though Wegovy is the formulation specifically licensed for weight management.

All of these are prescription-only medicines. Whether any of them is right for a given person is a decision made by a prescriber based on individual health history — not something to determine alone.

If you want to explore the differences between injectable options in more detail, see our overview of injectable weight loss medicines, or read about Mounjaro as a weight loss injection for more detail on tirzepatide specifically.

Injection sites for these medicines are typically the abdomen, outer thigh, or upper arm. Rotating sites with each injection is generally recommended to reduce the chance of skin irritation or changes at the injection site — your prescriber or the patient information leaflet that came with your pen will guide you on technique. According to NHS guidance, following the instructions provided with your medicine is important for safe use.

Staying consistent with a weekly injection schedule — and rotating sites correctly — is one of the practical challenges people on these medicines most commonly mention. GLP Trackr is built specifically for this.

The app's injection-site tracking and rotation feature lets you log exactly where each injection was given (abdomen, thigh, or upper arm) and keeps a history of your previous sites so it can suggest where to inject next. Over time, this takes the guesswork out of rotation entirely.

Alongside site tracking, dose logging means every injection is recorded with the date, time, and dose strength — so you always know when your last shot was and what stage of your programme you are at. Paired with dose reminders, it becomes much harder to accidentally miss a weekly injection or lose track of your schedule.

For a broader look at tracking your progress alongside your injections — weight, mood, side effects, and more — visit our guide to weight loss injections. If cost and getting the most from your prescribed medication is on your mind, our page on Mounjaro injection costs and value may also be useful.

GLP Trackr is free to try for 7 days and is available on the App Store and Google Play. Download it, log your very next injection, and let the app handle your rotation history from there.

Any questions about your injection technique, dose, or which medicine is right for you should always go to your prescriber or doctor — they know your full medical history. If you experience a side effect you are worried about, contact your healthcare professional promptly. You can also report side effects through your national reporting scheme (such as the UK's Yellow Card scheme or the equivalent in your country).