Wegovy v Mounjaro: What's the Difference?

The core difference between the two medicines lies in their active substances and how they act on the body's appetite-regulating pathways.

Wegovy (semaglutide)

Wegovy contains semaglutide, a GLP-1 receptor agonist. It mimics a naturally occurring hormone involved in appetite regulation, helping many people feel fuller sooner and reducing overall appetite. It is supplied as a pre-filled pen and is injected once a week. Dose strengths commonly referenced in clinical guidance include 0.25 mg, 0.5 mg, 1 mg, 1.7 mg, and 2.4 mg, with dosing typically starting low and increasing over time under prescriber supervision. You can read more about the Wegovy journey on our Wegovy overview page.

Mounjaro (tirzepatide)

Mounjaro contains tirzepatide, which acts on both GLP-1 and GIP receptors — making it a dual agonist. GIP (glucose-dependent insulinotropic polypeptide) is a second appetite-related hormone pathway. Whether this dual action makes a meaningful difference for any particular person is something only their prescriber can assess. Mounjaro is also injected once weekly via a pre-filled pen, with dose strengths commonly referenced at 2.5 mg, 5 mg, 7.5 mg, 10 mg, 12.5 mg, and 15 mg. Explore more on our Mounjaro information hub.

What they have in common

• Both are prescription-only medicines — neither can be obtained without a valid prescription from a qualified prescriber.
• Both are once-weekly subcutaneous injections.
• Both are subject to additional monitoring; any suspected side effects should be reported to your healthcare professional and your national reporting scheme (such as the UK's Yellow Card scheme).
• Neither is suitable for everyone — suitability is assessed individually by a prescriber.
• Both are typically started at a low dose and titrated upward according to a prescriber-led schedule.

For a more detailed side-by-side look, see our Mounjaro vs Wegovy comparison page. According to the electronic Medicines Compendium (eMC), full prescribing information and patient leaflets for both medicines are publicly available and worth reading alongside any conversation with your prescriber.

GLP Trackr is built for people already taking either Wegovy or Mounjaro, and it supports both medicines equally. Whichever you have been prescribed, staying consistent with your weekly injection schedule is one of the most important habits to build — and that's where the app's dose and injection logging earns its place.

Every time you inject, you can log the dose strength, date, time, and injection site. The app tracks your rotation history across sites (abdomen, thigh, upper arm) and suggests where to inject next — useful whether you're on a Mounjaro KwikPen or a Wegovy pre-filled pen. Alongside that, dose reminders mean a weekly injection is far less likely to slip your mind during a busy week.

Beyond the injection itself, the app's insights and analytics bring together your weight, energy, food, mood, and side-effect logs to show you what's actually shifting across your journey — the kind of joined-up picture that's genuinely useful to discuss at a prescriber appointment. If you're curious about how others on GLP-1 medicines are getting on, the context around Mounjaro's growing use and practical Mounjaro guidance may also be helpful reading.

The decision about which medicine is right for you — or whether to switch — belongs entirely with your prescriber, who knows your full medical history. GLP Trackr supports whatever you've been prescribed; it is not a substitute for clinical advice.

Ready to keep your weekly routine on track? GLP Trackr is available free on the App Store and Google Play — give it a try with a 7-day free trial and see how much easier consistent logging can make the journey.