What are the current weight loss injections available in the UK?

Which weight loss injections are currently licensed in the UK?

As of summer 2026, two injectable medicines are licensed by the MHRA specifically for weight management in adults: Mounjaro and Wegovy. Mounjaro contains tirzepatide, made by Eli Lilly, and comes as a once-weekly pre-filled KwikPen. Wegovy contains semaglutide, made by Novo Nordisk, and also delivers a once-weekly dose via a pre-filled pen. Both sit in the GLP-1 drug class, though they are not identical, tirzepatide is the only dual-agonist available, stimulating both GIP and GLP-1 receptors, while semaglutide targets GLP-1 alone.

A third option, Saxenda (liraglutide), holds a UK licence for weight management but requires a daily injection and is less commonly prescribed since the once-weekly alternatives became available. Orlistat, a capsule rather than an injection, also remains licensed. If you want a broader picture of the injectable options specifically, our guide to the different weight loss injections sets them out side by side.

One important distinction worth making early: Ozempic contains the same active ingredient as Wegovy (semaglutide) but is licensed for type 2 diabetes, not weight management. The two products are not interchangeable from a licensing perspective, and prescribing one for the other's purpose sits outside the product's UK authorisation.

How do these injections actually work in the body?

Both medicines slow the rate at which the stomach empties, which prolongs the feeling of fullness after eating. They also act on appetite-regulating areas of the brain, reducing hunger signals throughout the day. The result, for most people, is that they feel satisfied with less food and find cravings easier to manage, though the medicines work best alongside reduced-calorie eating and regular physical activity, not instead of them.

Mounjaro's dual action on GIP and GLP-1 receptors appears to produce stronger appetite suppression on average, which is reflected in the trial data. In the SURMOUNT-1 study, participants taking the 15mg dose achieved around 20–21% average body-weight reduction over 72 weeks, as published in the New England Journal of Medicine. The SURMOUNT-5 head-to-head trial (2025) confirmed that tirzepatide produced greater average weight loss than semaglutide 2.4mg over the same period.

Wegovy at its standard 2.4mg maintenance dose produced around 15% average weight reduction in its main STEP 1 trial. A higher 7.2mg dose was approved by the MHRA in January 2026 and a dedicated single-dose 7.2mg pen followed in April 2026, narrowing the gap with tirzepatide results. More detail on how these injections work is available if you want to go deeper on the mechanisms before your consultation.

What are the most common side effects to be aware of?

Both medicines share a similar side-effect profile, dominated by gastrointestinal symptoms: nausea, loose stools, constipation, reflux and burping are the ones patients mention most. These tend to be most noticeable in the first few weeks of treatment or after a dose step-up, and they usually ease as the body adjusts. Fatigue, headaches and dizziness are also reported, particularly early on.

Pancreatitis is a less common but more serious potential side effect. In January 2026 the MHRA issued a Drug Safety Update flagging acute pancreatitis across the GLP-1 class; the signal to watch for is severe stomach pain that radiates to the back, with or without vomiting, which warrants urgent medical attention rather than waiting to see if it settles. Suspected side effects from any medicine can be reported through the Yellow Card scheme.

Titration schedules (where treatment starts at a low dose and increases gradually) exist largely to keep these side effects manageable. Both Mounjaro and Wegovy start at lower doses than the eventual maintenance dose. The schedule is set by your prescriber and the patient information leaflet; it is not something to adjust based on how you feel without clinical input.

Who can access these injections, and how does the process work?

For private prescription, both medicines are licensed for adults with a BMI of 30 or above, or a BMI of 27 or above alongside at least one weight-related condition such as high blood pressure, type 2 diabetes, high cholesterol or obstructive sleep apnoea. BMI thresholds are adjusted downward for some ethnic backgrounds under UK guidance. If you are curious how the options compare at a glance, our guide to the different weight loss injections available in the UK covers the key distinctions clearly. Eligibility is a clinical judgement, though, BMI gets you to the table, not automatically through the door.

On the NHS, access follows NICE guidance and is considerably more restricted. Mounjaro (NICE TA1026, December 2024) currently requires a BMI of 40 or above plus four or more qualifying conditions to be eligible in the first cohort, with further cohorts opening through 2026 and into 2027. If you are trying to get your bearings on the licensed products available today, a closer look at the 3 weight loss injections that currently hold MHRA authorisation for weight management may help you understand where each one fits. Wegovy requires referral to a specialist weight management service under NICE TA875 and is subject to long waiting lists in most areas. The treatment overview page explains both routes plainly if you are weighing up your options.

The private route through a regulated online pharmacy removes the waiting list but does not remove the clinical assessment, a prescriber still reviews your answers, checks your records and decides suitability. At nume, that review is carried out the same working day by a GPhC-registered Independent Prescriber. You can read more about how we work before starting. If you would like to understand what a weight loss injection actually involves before committing to a consultation, our dedicated page walks you through the process step by step. If you are unsure whether you might be suitable, check your eligibility with a free consultation, it costs nothing and carries no obligation.