Weight Loss Injections: Approvals, Access, and Tracking Your Journey

Regulatory approval means that an independent medicines authority has reviewed clinical evidence and determined that a medicine meets defined standards of safety, quality, and efficacy for a specified use. In the UK, this is overseen by the Medicines and Healthcare products Regulatory Agency (MHRA). Similar processes exist in other countries through their own national authorities.

Both Mounjaro and Wegovy are prescription-only medicines (POMs). That means they can only be legally supplied when prescribed by a qualified healthcare professional — suitability is assessed individually, taking into account a person's medical history, other medicines, and clinical circumstances. No approval process changes that individual assessment; it simply establishes that the medicine is a legitimate, licensed option for prescribers to consider.

Mounjaro (tirzepatide)

Mounjaro contains tirzepatide, a dual GIP and GLP-1 receptor agonist, and is supplied as a once-weekly pre-filled injection pen. It carries a black triangle (▼) designation in the UK, meaning it is subject to additional monitoring. Any suspected side effects should be reported to your healthcare professional and to your national reporting scheme (such as the UK's Yellow Card scheme).

Wegovy (semaglutide)

Wegovy contains semaglutide, a GLP-1 receptor agonist, and is also administered as a once-weekly injection. Like Mounjaro, it is prescription-only and carries the black triangle (▼) status in the UK. Side effects can similarly be reported through your national pharmacovigilance scheme.

For a broader look at how these injections work and what to expect, see our guide to weight loss injections. If you have questions about what is involved in obtaining a prescription, the page on getting a weight loss injection covers the general process in more detail.

Once you are prescribed a weight loss injection, staying consistent with your weekly schedule and injection-site rotation is one of the most practical things you can do to support your treatment. GLP Trackr's injection-site tracking and rotation feature is built specifically for this: each time you inject, you log the site — abdomen, thigh, or upper arm — and the app keeps a history and suggests where to inject next, so rotation becomes automatic rather than something you have to remember yourself.

Alongside site rotation, the app's dose logging means every injection is recorded with its date, time, and dose strength, giving you a clear, timestamped record that is straightforward to refer back to or share with your prescriber at appointments. Dose reminders can also be set so a weekly injection is never accidentally missed.

If you experience side effects at any point — nausea, fatigue, or injection-site reactions are among the most commonly reported — you can log these in the side-effect tracker and watch for patterns over time. That log can be genuinely useful to bring to a conversation with your healthcare professional.

GLP Trackr supports people already on both Mounjaro and Wegovy, wherever they are in the world. You can explore more about choosing and managing your injection or read about what to consider once you have a prescription in our related guides. For the full picture on injectable weight loss medicines, visit the weight loss injections hub.

A note on medical decisions: GLP Trackr records your journey and helps you spot patterns — it is not a substitute for your prescriber's guidance. Any questions about your dose, your injection schedule, or whether this treatment is right for you should always be discussed with your healthcare professional, who knows your full medical history.

Ready to take control of your injection routine? Download GLP Trackr on the App Store or Google Play and start a free 7-day trial — your dose log, site rotation history, and progress tracking are all waiting for you.