Different GLP-1 Medicines Explained (October 2026)

01 · The core answer

The different GLP-1 medicines available in the UK

There are three main active ingredients behind the GLP-1 medicines most UK adults hear about: tirzepatide, semaglutide and liraglutide. For a deeper breakdown, see our guide to the types of GLP-1 medicines and the page on individual GLP-1 drugs.

Check the tablets' own product information, or ask the prescriber, rather than assuming they work like the pens.²⁰²¹

02 · Your decision

Which GLP-1 is considered the best?

No GLP-1 is best for everyone; the right one depends on your health, tolerance and schedule. Mounjaro and Wegovy are both effective licensed treatments, and individual results vary. A head-to-head trial exists for tirzepatide against semaglutide (SURMOUNT-5), but trial averages do not predict your own result.¹⁵

Practical questions matter more than league tables. Do you prefer a weekly or daily routine? Have you tolerated one medicine badly? Do other conditions or medicines change the picture? A GPhC-registered prescriber can weigh these up in a free consultation. Our weight loss clinic page explains the wider service.

Related guide: Recombinant glp-1.

03 · How Mounjaro differs

How Mounjaro differs from other GLP-1 medicines

Mounjaro is the brand name for tirzepatide, a once-weekly injectable prescription medicine made by Eli Lilly. In the UK it is licensed for weight management in adults and for type 2 diabetes.¹ It comes as a pre-filled multi-dose pen (KwikPen) in six strengths: 2.5mg, 5mg, 7.5mg, 10mg, 12.5mg and 15mg.¹

Tirzepatide is the first treatment of its kind to activate two natural gut-hormone receptors at once: GIP and GLP-1.¹ Together these help regulate appetite, slow how quickly the stomach empties, and improve the way the body responds to insulin.¹ This dual action is what distinguishes Mounjaro from single-action GLP-1 medicines such as semaglutide (Wegovy/Ozempic).¹

So, is GLP-1 the same as Mounjaro? Not quite. Mounjaro acts on the GLP-1 receptor but also on GIP, so it is usually described as a GIP and GLP-1 medicine rather than a plain GLP-1 drug.

04 · Wegovy, Ozempic and liraglutide

Wegovy, Ozempic and liraglutide compared

Wegovy and Ozempic both contain semaglutide, a single-action GLP-1 medicine. 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. The brand names are not interchangeable, because each is licensed and dosed for its own purpose.

Wegovy pens come in 0.25mg, 0.5mg, 1mg, 1.7mg and 2.4mg strengths, given once weekly. Mounjaro also starts low and steps up, but its ladder runs from 2.5mg to 15mg in steps of 2.5mg, with at least 4 weeks on each dose, depending on how you respond.¹

Liraglutide, sold as Saxenda and in products such as Erly, is supplied at a concentration of 6mg per millilitre and is a daily injection, unlike the once-weekly pens. If a label mentions 6mg/ml, that describes the liquid strength, not a dose; our page on how concentration is expressed explains the difference.

05 · Types, tablets and the wider family

Tablets, brands and other 'GLP' names

Tablet GLP-1 options now exist alongside the injections. Wegovy tablets contain oral semaglutide and Foundayo contains orforglipron.²⁰²¹ Each has its own licence, so do not compare their trial results with the pens as if they were head to head.

You will also see questions about 'GLP-2' or 'GLP-3'. These are not tiers of a ranking. Different gut hormones have different jobs, and GLP-1 is the one targeted by the medicines above. No such ladder exists in which a higher label means better treatment, so a number in a name tells you nothing about quality.

06 · Speed and combining

Fastest results, and taking more than one

No GLP-1 is reliably fastest, because weight loss on Mounjaro is gradual by design. The early weeks on 2.5mg are an adjustment phase and losses are usually modest; most measurable progress builds from 5mg onward, month by month.¹ Trials measured results at 72 weeks, so think in months, not days, and judge progress by trend rather than individual weigh-ins.

Your prescriber reviews response. If you have lost less than 5% of your starting weight after 6 months on the highest dose you can tolerate, they will discuss whether continuing or stopping is right for you.¹

Can you take two GLP-1 medicines together? Mounjaro must not be combined with other GLP-1 medicines, unlicensed 'research' peptides or compounded copies. These combinations have no safety data and no regulated supply chain. If one medicine is not working for you, ask your prescriber about your options within the licence.

07 · Choosing and NHS access

Choosing between GLP-1 brands, and NHS access

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.⁴⁶ Full rollout is expected to take years, which is why many people who meet the licensed criteria choose regulated private treatment. NHS access to Wegovy runs through specialist weight-management services; ask your GP.

Whichever route you take, use a GPhC-registered pharmacy and a prescriber review. Counterfeit and unregulated injectables are a real risk, so avoid anyone offering to supply without a consultation or prescription. You can check any pharmacy on the GPhC register; ours is GPhC 9012878.⁷

Our own supply is official LillyDirect supply, sourced directly from Eli Lilly, and our free consultation is reviewed by a GPhC-registered prescriber. For a related overview of labels and manufacturers, see our guide to brands of weight loss injections.