New Weight Loss Injections 2025: What's Actually Available in the UK

What changed for these injections in 2025, and why it matters

The biggest shift in 2025 has been access, not the medicines themselves. Mounjaro had already been licensed for weight management in the UK before 2025, but NICE's formal recommendation (TA1026, published December 2024 and updated September 2025) opened a path to NHS prescribing for the first time. From June 2025, adults with a BMI of 40 or above plus four or more qualifying weight-related conditions became eligible for NHS tirzepatide. That rollout is phased and narrow right now, and many people who could benefit clinically don't yet meet the NHS threshold or would face a significant wait.

Wegovy also moved in 2025: a higher 7.2mg maintenance dose was approved by the MHRA in January 2026 (following work that ran through 2025), with a dedicated single-dose pen approved in April 2026. Trials at 7.2mg reported around 20.7% average weight loss over 72 weeks, which brings Wegovy's ceiling much closer to Mounjaro's. If you want to understand how the landscape looked as these changes were taking shape, our guide to the new weight loss injection options emerging in 2024 gives useful background on how we got here. You can read more about how both injections work and what the licensing covers if you're starting from scratch.

The short version: 2025 brought more options, clearer evidence and a slowly widening NHS door. For most people reading this, private prescription through a regulated pharmacy is still the practical route.

The actual decision: Mounjaro or Wegovy, and why it's a clinical call

People often arrive at this question expecting a definitive ranking. The evidence points toward Mounjaro producing greater average weight loss across the board, a finding confirmed in the SURMOUNT-5 head-to-head trial published in the New England Journal of Medicine (2025), which compared tirzepatide directly against semaglutide 2.4mg in adults with obesity. Tirzepatide came out ahead on average body-weight reduction.

But the right medicine for you depends on factors that a number on a chart can't settle. Your current medications matter: women taking oral contraceptives who start Mounjaro are advised to add a non-oral method of contraception for the first four weeks of treatment and for four weeks after each dose increase, because absorption of the pill may be reduced. Wegovy doesn't carry the same evidence of reduced pill effectiveness. Your history of GI side effects, any previous experience with either class, and whether you've already been stable on one of them, all of these are things a prescriber weighs. The broader picture of how these medicines differ pharmacologically is worth understanding before your consultation.

On eligibility: both are licensed for adults with a BMI of 30 or above, or 27 and above where at least one weight-related condition is present, such as high blood pressure, type 2 diabetes or obstructive sleep apnoea. BMI thresholds run 2.5 kg/m² lower for some ethnic backgrounds under UK guidance. Neither is licensed for anyone under 18, or for use during pregnancy or breastfeeding.

Side effects worth knowing before you decide

The side-effect profile for both injections is led by the digestive system: nausea, loose stools, constipation, reflux and tiredness are the most commonly reported, particularly in the early weeks and after each dose step up. For most people they settle. The NHS tirzepatide page covers the full list for Mounjaro in plain language, and it's worth reading before you start.

One safety point that applies to both: the MHRA issued a Drug Safety Update in January 2026 specifically on GLP-1 medicines and acute pancreatitis. Severe, persistent stomach pain that radiates toward the back (with or without vomiting) warrants urgent medical attention. This is infrequent but serious. Anyone on these medicines should know the sign. Our page on the risks people actually ask about addresses this in more detail.

Practically: both Mounjaro and Wegovy are stored in the fridge (2–8°C), many people keep the current pen in the fridge door so it's easy to find on injection day. There's a limited window for room-temperature storage if you're travelling; the Patient Information Leaflet that comes with the pen gives the exact timeframes.

Getting a prescription in 2025: NHS versus private

The NHS route for Mounjaro is real but still limited to a narrow cohort. From June 2026, Cohort 2 expanded eligibility to adults with a BMI of 35–39.9 plus four or more qualifying conditions, a step forward, but still far from covering everyone who could benefit. GP practices can now prescribe under the updated GP contract, though participation varies by practice and area. For Wegovy, NHS access runs through specialist weight management services, where waiting lists remain long in most parts of England.

Private prescription through a regulated online pharmacy is the route most people are taking in 2025, and our guide to the best weight loss injections available in 2025 can help you compare what's on offer before you commit. When considering any online provider, you can verify that a pharmacy is GPhC-registered at the GPhC register, it takes about 30 seconds and is the single most useful check you can do. For context on what private treatment typically costs, our page on weight loss injection pricing in the UK sets out what the market looks like and what a legitimate price includes.

At nume, every consultation is reviewed the same day by a GPhC-registered Independent Prescriber. A real clinician reads your answers. If approved, treatment is dispatched the same day for free next-working-day delivery. For anyone who wants to understand the full range of what's available, our weight loss treatment overview covers all the options we assess people for.

If you're ready to talk through which injection makes clinical sense for your situation, you're welcome to speak to our prescribers through a free consultation.