Weight Loss Injection Drug Names in the UK (October 2026)

01 · The short list

The weight loss injection names you will see in the UK

Three active ingredients cover most prescribing of weight loss injections: tirzepatide, semaglutide and liraglutide. Semaglutide and liraglutide are each sold under more than one brand, so the same ingredient can appear on different boxes.

Mounjaro is the brand name for tirzepatide, a once-weekly injectable prescription medicine made by Eli Lilly.¹ Its dual action distinguishes it from single-action medicines such as semaglutide (Wegovy/Ozempic).¹ If you want the same list organised by wording, see our guides to weight loss injection names and names of weight loss drugs.

02 · Your next step

Which name is relevant to you?

The right medicine is a prescriber's decision, not a name you pick from a list. They consider your health, your other medicines and your goals. If you are researching Mounjaro specifically, you can read about the Mounjaro pen and its prices: a 2.5mg starter pen has a standard price of £169.99, and all six doses are in stock.

If you simply want a broader overview of treatment options, our weight loss clinic page explains how a free online consultation works. Prices checked 10 October 2026.

03 · Mounjaro (tirzepatide)

Mounjaro (tirzepatide)

Mounjaro is licensed in the UK for weight management in adults, and for type 2 diabetes. It comes as a pre-filled multi-dose pen (KwikPen) in six strengths: 2.5mg, 5mg, 7.5mg, 10mg, 12.5mg and 15mg.¹ Each KwikPen contains four weekly doses.¹³

Everyone starts on 2.5mg once a week. After at least 4 weeks the dose increases to 5mg, and can then step up by 2.5mg at a minimum of 4-week intervals up to a maximum of 15mg weekly, depending on how you respond and tolerate it.¹ Higher is not automatically better, and your prescriber guides the pace.

04 · Wegovy and Ozempic

Wegovy and Ozempic (semaglutide)

Wegovy and Ozempic are brand names for semaglutide, a single-action medicine that is injected once weekly. Ozempic is licensed for type 2 diabetes only; it is not a UK weight-loss medicine, and a regulated UK pharmacy will not supply it for weight loss. Because they share an active ingredient, you should never use both at once.

Wegovy pens come as 0.25mg, 0.5mg, 1mg, 1.7mg and 2.4mg. The dose steps up after 4 weeks on each of 0.25mg, 0.5mg, 1mg and 1.7mg, so the 2.4mg maintenance dose starts from week 17; that is the licensed maintenance dose for weight management. Wegovy also now has a tablet form, which is a separate product; see current Wegovy tablet prices on its product page rather than relying on a figure here.

NHS access to Wegovy runs through specialist weight-management services; ask your GP.

05 · Liraglutide and Saxenda

Liraglutide (Saxenda)

Liraglutide is sold as Saxenda, and in products such as Erly. It is supplied at a concentration of 6mg/ml and is a daily injection, unlike once-weekly Mounjaro and Wegovy. Because it is taken every day, some people find it more demanding to stick with.

For a longer list that includes older and newer names, see weight loss injections medication names and weight loss pens names.

06 · Not an injection?

Weight loss drugs that are not injections

Some people want a weight loss drug that is not an injection. Tablet options exist: Wegovy tablets (oral semaglutide) and Foundayo (orforglipron) are both licensed tablet products with their own product information. They are different medicines from Mounjaro, so do not compare their trial results with Mounjaro's as if they were head to head.

Other prescription and over-the-counter products exist too, and figures vary, so your prescriber can advise. Be cautious of low-cost supplements sold with dramatic weight-loss claims: they carry no clinical oversight and are not equivalent to licensed medicines. Older drugs with a troubled history are covered in our piece on the fen-fen weight loss drug.

07 · Interactions and safety

Drug interactions with weight loss injections

Because Mounjaro slows stomach emptying, it can affect how quickly some oral medicines are absorbed, particularly when you start treatment or increase the dose. Tell your prescriber about everything you take, especially warfarin or other narrow-margin medicines, insulin, or sulfonylureas, where doses may need reducing to avoid low blood sugar. No adjustment is needed for paracetamol.¹

Report any suspected side effect through the MHRA Yellow Card scheme.¹⁹ Beware of anyone offering to supply these medicines without a consultation or prescription: the MHRA has issued alerts after fake pens were identified.⁷

08 · Serious side effects

Serious side effects: when to get help straight away

Serious side effects are uncommon but need urgent attention. Seek immediate medical help for: severe, persistent stomach pain that may spread to your back, with or without vomiting (possible pancreatitis); pain in the upper right abdomen, fever or yellowing of skin/eyes (possible gallbladder problems); or signs of a severe allergic reaction such as swelling of the face or throat and difficulty breathing. If you take insulin or a sulfonylurea alongside Mounjaro, watch for low blood sugar (shakiness, sweating, confusion) — your prescriber may need to adjust those medicines.¹

09 · NHS or private?

NHS or private supply

Mounjaro is available on the NHS, but access is being phased in over several years. NICE recommends it for adults with a BMI of at least 35 plus at least one weight-related condition, and the NHS primary-care rollout began in June 2025 with the highest-need groups first.⁴ Full rollout is expected to take years, which is why many people who meet the licensed criteria choose regulated private treatment.

Mounjaro (tirzepatide) is a prescription-only medicine, supplied only after an online consultation reviewed by a GPhC-registered prescriber. It is used alongside a reduced-calorie diet and increased physical activity. Individual results vary.