Mounjaro®
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The misconception worth correcting first: 'GLP-1' and 'semaglutide' are not the same thing
Most people arrive at this question after seeing both terms used loosely online, sometimes as if they mean the same medicine. They do not. GLP-1 is a class label (like saying 'antibiotic') while semaglutide is a single compound within that class, in the same way that amoxicillin is one antibiotic among many. Several distinct GLP-1 receptor agonists are now available in the UK, each with its own licensed indications, trial data and dosing schedule. Semaglutide happens to be the one with the highest public profile, partly because of Wegovy's availability through private providers and partly because of the long-running (and sometimes confused) conversation around Ozempic versus Wegovy.
Tirzepatide, sold as Mounjaro, adds a second mechanism: it activates both GLP-1 and GIP receptors simultaneously. Calling tirzepatide a 'GLP-1 medicine' is technically accurate but incomplete, its dual-receptor action is the reason its trial results differ from semaglutide's. Other GLP-1 medicines on the UK market include liraglutide and dulaglutide, though their licensed indications and clinical profiles diverge significantly from semaglutide's; the liraglutide versus semaglutide distinction is worth reading separately if that comparison is relevant to you.
The practical upshot: when a friend says they are 'on a GLP-1', that tells you the mechanism but not the medicine, the dose, or the licensed purpose.
How semaglutide sits within the GLP-1 family: licensed uses and what they mean in the UK
Semaglutide exists in three UK-licensed forms, and the differences between them matter clinically. Wegovy (2.4mg weekly injection, with a new 7.2mg higher-dose pen approved by the MHRA on 14 April 2026) is licensed for weight management in adults with a BMI of 30 or above, or 27 or above with at least one weight-related condition. Ozempic is also semaglutide, but it is licensed for type 2 diabetes, not weight management, and prescribing it for weight loss is off-label. Wegovy tablets, approved by the MHRA on 11 June 2026, are the first oral GLP-1 medicine licensed in the UK for weight management, titrating from 1.5mg daily up to a 25mg maintenance dose. Saxenda (liraglutide, a different GLP-1 medicine) is licensed for weight management but is a daily injection rather than weekly.
The NICE recommendation for semaglutide (Wegovy) sets specific NHS access thresholds: BMI of 35 or above with at least one weight-related comorbidity, within a specialist weight management service, for a maximum of two years, per NICE technology appraisal TA875. Private eligibility follows the licensed SmPC criteria, which are somewhat broader. Lower BMI thresholds apply for some ethnic backgrounds under UK guidance.
If you want to explore all licensed weight-loss options side by side, the weight-loss treatment overview covers them in one place.
GLP-1 medicines compared: a factual snapshot
| Medicine | Class | UK weight-loss licence | Route | Trial weight loss (headline figure) |
|---|---|---|---|---|
| Semaglutide (Wegovy injection) | GLP-1 receptor agonist | Yes (MHRA licensed | Weekly subcutaneous injection | ~15% average over 68 weeks (STEP 1, NEJM) |
| Semaglutide (Wegovy tablet) | GLP-1 receptor agonist | Yes) MHRA licensed June 2026 | Once-daily oral tablet | ~13.6% average over 64 weeks (OASIS 4) |
| Tirzepatide (Mounjaro) | Dual GIP + GLP-1 receptor agonist | Yes (MHRA licensed | Weekly subcutaneous injection | ~20–21% average over 72 weeks (SURMOUNT-1, NEJM) |
| Semaglutide (Ozempic) | GLP-1 receptor agonist | No) licensed for type 2 diabetes only | Weekly subcutaneous injection | Not licensed for this purpose |
| Liraglutide (Saxenda) | GLP-1 receptor agonist | Yes, licensed; not dispensed by nume | Daily subcutaneous injection | ~8% average over 56 weeks (SCALE programme) |
Numbers are from published clinical trials and cited regulatory sources; individual results vary, and these figures should never be read as personal predictions. The dulaglutide versus semaglutide comparison and the retatrutide versus semaglutide page cover two further GLP-1 comparisons in detail for readers researching the wider pipeline.
What this means when you are choosing a treatment
Knowing that semaglutide is a GLP-1 medicine tells you the mechanism (it slows gastric emptying, reduces appetite and influences blood-sugar regulation through the GLP-1 receptor pathway) but it does not tell you which medicine suits your health history, your current medications or your daily routine. The Wegovy tablet, for instance, has a strict morning routine: taken on an empty stomach with a small amount of plain water, at least 30 minutes before coffee or breakfast. Practical? For some people, yes. For others, fitting that window around a school run or an early gym session is harder than keeping a weekly pen in the fridge door. That kind of everyday detail shapes adherence, and adherence shapes outcomes.
Side effects across the GLP-1 class are broadly similar (nausea, changes in bowel habit and fatigue are the most commonly reported, particularly around dose increases) though individual tolerability varies. The NHS semaglutide page lists the full profile for Wegovy specifically. Tirzepatide's dual-mechanism profile produced greater average weight loss in the SURMOUNT-5 head-to-head trial against semaglutide 2.4mg, but the higher 7.2mg Wegovy dose narrows the gap; the right choice depends on more than one number.
Which medicine suits you is a clinical decision our prescribers make with you. Comparing the two main options licensed for weight management in the UK is a useful starting point (how oral options stack up against Wegovy is another angle worth reading) but the decision belongs in a proper consultation. Speak to our prescribers by starting your free consultation, and a GPhC-registered Independent Prescriber will review your answers the same day.
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