The names of all weight loss injections licensed in the UK

You've heard several names. Here's what each one actually is.

The confusion is understandable. Type a search into your phone and you'll see Mounjaro, Wegovy, Ozempic, Saxenda, Zepbound, and occasionally Victoza all clustered together as though they're interchangeable. They're not.

Weight loss injections licensed for that specific purpose in the UK are Mounjaro and Wegovy. That's the complete list. Everything else either treats a different condition, isn't authorised here, or has been discontinued. Mounjaro contains tirzepatide and works on two gut-hormone receptors simultaneously (GIP and GLP-1) which makes it the only dual-agonist weight management medicine licensed in the UK. Wegovy contains semaglutide and acts on GLP-1 receptors alone. Both slow gastric emptying and reduce appetite, and both are delivered as a once-weekly injection you do yourself, usually into the abdomen, thigh or upper arm.

Ozempic is also semaglutide (the same active ingredient as Wegovy) but it carries a UK licence for type 2 diabetes management, not weight loss. Prescribing it specifically for weight loss would be off-label, and the NHS semaglutide medicines page is clear about the distinction between the two products. Saxenda (liraglutide) was licensed for weight management but is no longer one to pursue through nume's service. If you're trying to make sense of what the names of weight loss injections actually refer to, that page unpacks each one so you're not left guessing. Zepbound is the US brand name for tirzepatide; in the UK, tirzepatide is Mounjaro, full stop, Zepbound has no UK regulatory status.

One misconception worth gently setting down: these are not "diet jabs" that work regardless of lifestyle. Every licence for both medicines specifies use alongside a reduced-calorie diet and increased physical activity. The injection changes your biology; the rest is still on you, though most people find that considerably easier once appetite genuinely settles.

How the licensed names sit within the UK's prescribing rules

Both Mounjaro and Wegovy carry a Black Triangle (▼) designation from the MHRA, which simply means they're under additional post-market monitoring as relatively new medicines, not that they're experimental or unsafe. They went through full regulatory review before approval.

NICE has separately assessed both. Tirzepatide received a NICE recommendation in December 2024 (updated September 2025) for adults with a BMI of 35 or above plus at least one weight-related condition such as high blood pressure, type 2 diabetes, high cholesterol, obstructive sleep apnoea or cardiovascular disease. Lower BMI thresholds apply for some ethnic backgrounds under NICE technology appraisal TA1026. Semaglutide (Wegovy) holds a separate NICE recommendation under TA875 but with tighter conditions, including a maximum treatment duration of two years within specialist weight management services.

Private prescribing follows the medicines' own licences rather than the NHS eligibility criteria, so the thresholds can differ. The SmPC for Mounjaro sets the private eligibility at a BMI of 30 or above, or 27 or above with at least one weight-related condition. A prescriber makes the final call by assessing the full clinical picture, BMI alone has never been the only factor. If you want a more granular comparison before your consultation, you can read about the weight loss injections names used in the UK and what each means clinically.

For anyone researching cost alongside eligibility, our treatment page sets out what's included in a private prescription through nume, from the consultation through to delivery, one place where pricing is shown transparently.

Side effects and what to watch for across both medicines

The side-effect profiles of Mounjaro and Wegovy overlap considerably because both act on GLP-1 receptors. Nausea is the most commonly reported, particularly in the first few weeks of treatment or after a dose increase. Vomiting, diarrhoea, constipation, indigestion and fatigue also feature regularly in trial data and in clinical practice. Most of these settle as the body adjusts, though not always quickly.

A safety communication worth knowing: the MHRA issued a Drug Safety Update in January 2026 specifically about acute pancreatitis and GLP-1 medicines. It's an infrequent but potentially serious side effect. Severe, persistent stomach pain (especially if it radiates towards the back) with or without vomiting warrants urgent medical attention, not a wait-and-see approach. You can report any suspected side effect, or a suspect seller, directly at the MHRA Yellow Card scheme.

Both medicines are not recommended during pregnancy, while breastfeeding, or for those actively trying to conceive. Neither is licensed for people under 18. Women using oral contraceptive pills who start tirzepatide should add a non-oral method of contraception for the first four weeks of treatment and for four weeks after each dose increase, as tirzepatide can affect pill absorption. Our clinical team explains this at consultation, it's the sort of detail that's easy to miss when you're reading a box insert at midnight.

If you have a surgical procedure planned, the anaesthetic team needs to know you're on either medicine. Tell them before the day; don't leave it to a pre-op form. If you're also managing an inflammatory condition, it's worth reading about weight loss injections and rheumatoid arthritis, as there are specific clinical considerations that apply alongside the day-to-day realities covered there.

Getting a legitimate prescription for either medicine

Both Mounjaro and Wegovy are available through NHS services, but access is phased and not yet open to most people, NHS tirzepatide prescribing began rolling out from June 2025 and is still limited to specific BMI and comorbidity thresholds that will expand in stages through 2027. Wegovy is available through specialist weight management services under TA875, where waiting lists tend to be long.

Private prescribing through a regulated online pharmacy offers a route that doesn't depend on NHS cohort eligibility or a referral. The legal requirement is identical either way: a clinical assessment by a registered prescriber, with a prescription issued only if the medicine is appropriate for you. At nume, that assessment is carried out by a GPhC-registered Independent Prescriber (a person, not automated screening) and photo-ID verification and live weight confirmation happen before any prescription is issued.

When choosing any online pharmacy, verify it on the GPhC pharmacy register before handing over any personal information or payment. Sellers offering these medicines without a clinical assessment are breaking UK law, and fake pens have been seized in significant numbers, some containing insulin rather than the stated medicine. The risk is real. It also helps to understand the names of weight loss injection drugs and how they differ, so you can recognise what you're being offered and whether it's legitimate. If you'd like to check what the process of obtaining weight loss injections legitimately looks like step by step, that page covers it in detail. Our clinical team and service background are also there if you want to know who's behind the prescribing decisions.

When you're ready, you can start your free consultation with our prescribers. No referral needed, and the consultation itself costs nothing.