The names of the weight loss injection drugs available in the UK

Which brand names should you actually be looking for?

A question our prescribers hear most weeks goes something like this: "I've seen Ozempic mentioned everywhere, is that the one for weight loss?" It isn't. Ozempic contains semaglutide, but its UK licence covers type 2 diabetes management, not weight loss. The version of semaglutide that carries a UK weight-management licence is Wegovy, which comes as a pre-filled once-weekly injection pen. These are different products with different licensed indications, even though the active molecule is the same.

The other drug licensed for weight loss in UK adults is tirzepatide, sold under the brand name Mounjaro. Eli Lilly manufactures it as a pre-filled KwikPen, also injected once a week. You can read a fuller breakdown of what these drugs are and how they work if you want the mechanism in more depth. For now, the short version is: Mounjaro and Wegovy are the two names you're looking for. Everything else circulating online (Ozempic for weight loss, compounded semaglutide, "skinny jabs" from unverified sellers) sits outside the licensed, regulated framework that makes these medicines safe to use.

Both drugs are classed as Black Triangle (▼) medicines by the MHRA, meaning they are subject to additional monitoring. That is routine for newer medicines and is not a concern in itself; it exists so that any emerging safety signals are captured quickly. The NHS provides patient-level information on tirzepatide and on semaglutide through its medicines pages, which are a sensible first stop for factual detail.

What makes these two drugs different from each other?

Semaglutide (Wegovy) is a GLP-1 receptor agonist. It mimics a gut hormone that signals fullness, slows the rate at which the stomach empties, and reduces appetite over time. The standard titration pathway moves from 0.25 mg up to a 2.4 mg maintenance dose, stepped up roughly every four weeks by the prescriber. In January 2026 the MHRA also approved a higher 7.2 mg dose, widening the ceiling for people who need it. The STEP 1 trial, published in the New England Journal of Medicine, found an average weight reduction of around 15% over 68 weeks at the 2.4 mg dose. You can explore how weight loss injections work in practice for a more detailed look at what those trial figures mean day to day.

Tirzepatide (Mounjaro) adds a second mechanism. It is a dual GIP and GLP-1 receptor agonist (the only such medicine licensed in the UK) which means it acts on two of the gut-hormone pathways involved in appetite and blood-sugar regulation rather than one. Treatment starts at 2.5 mg and can be titrated up to 15 mg. In the SURMOUNT-1 trial (2,539 participants), average body-weight reduction reached around 20 to 21% at the 15 mg dose over 72 weeks; in the SURMOUNT-5 head-to-head comparison, tirzepatide produced greater average weight loss than semaglutide 2.4 mg. Understanding the names of these injections is one thing; knowing how their mechanisms differ is what helps a prescriber decide which suits your situation.

Neither drug is suitable for everyone, and BMI alone doesn't determine suitability. The prescriber looks at the full clinical picture (existing conditions, other medicines, history) before deciding which, if either, is appropriate.

Who holds a UK licence to prescribe these, and through which routes?

Both tirzepatide and semaglutide are Prescription-Only Medicines under the Human Medicines Regulations 2012. That means the only legal route to them is a prescription issued by a qualified prescriber following a clinical assessment. GPs can prescribe tirzepatide under the 2026/27 GP contract, though participation is voluntary and NHS access depends on meeting strict phased criteria; the NHS England pages on weight management injections set out those criteria clearly. Wegovy on the NHS flows through specialist weight management services, where waiting lists are often lengthy.

Private routes through a GPhC-registered online pharmacy are legal and available without a referral, provided clinical assessment takes place. You can verify any online pharmacy on the GPhC register before sharing any personal information. At nume, every consultation is read by a GPhC-registered Independent Prescriber (a real clinician, not software) on the same day it's submitted. If you're comparing costs and want to understand what private treatment actually involves, our treatment page sets out exactly what's included. For a broader view of the options, the weight loss treatments overview covers both injectable and oral routes.

One thing worth flagging: the MHRA has warned repeatedly about fake weight loss pens sold through social media and unverified websites, some of which have contained insulin rather than the drug on the label. Protecting yourself is straightforward, only obtain these medicines through a pharmacy you can verify on the GPhC register, and never from a seller who offers them without a prescription being issued first.

Are any other injectable weight loss drugs available in the UK?

Liraglutide, sold as Saxenda, also holds a UK licence for weight management and is a once-daily GLP-1 injection. It is an older medicine in the same class, still available privately in the UK, though it is not dispensed by nume. Pages covering all the injectable weight loss drugs licensed in the UK go into more detail on liraglutide's profile if that comparison is useful. The headline is that tirzepatide and semaglutide (Wegovy) are the two medicines where the trial evidence and regulatory activity are most current, and both are available through a clinical consultation with our prescribers.

Orlistat is sometimes mentioned alongside injectable medicines. It's a capsule, not an injection, and it works by blocking fat absorption rather than acting on appetite hormones, a different mechanism and a different conversation. For injectable treatment specifically, Mounjaro and Wegovy are where the evidence sits today. If you want to explore which might fit your circumstances, the sensible next step is a clinical conversation rather than a search engine.