Wegovy Substitutes: Making Sense of Your Options

Why people look for a substitute in the first place

A question our prescribers hear most weeks goes something like: "Wegovy keeps going out of stock at my pharmacy, what can I take instead?" Supply disruption has been the most common trigger, but it's not the only one. Some people find the injection format difficult to manage long-term. Others experience side effects they can't tolerate at higher semaglutide doses. A smaller group simply read the trial data and want to know whether a different medicine might work better for them.

None of those are unreasonable starting points. But it matters to say clearly: switching weight-management medicines is a clinical decision, not a consumer one. The active ingredient, the mechanism, the dose schedule and your own medical history all interact in ways that a prescriber needs to assess. What follows is an honest map of what's licensed in the UK, so you arrive at that conversation informed.

You can read more about how Wegovy works and its licensed place in UK weight management if you want the baseline before comparing.

Tirzepatide (Mounjaro): the most clinically distinct substitute

Tirzepatide is made by Eli Lilly and sold as Mounjaro. It's a once-weekly subcutaneous injection, like Wegovy, but the mechanism is meaningfully different: it activates both GLP-1 and GIP receptors, making it the only dual-agonist weight-loss medicine licensed in the UK. That dual action appears to produce stronger appetite suppression in many people, and the evidence reflects it.

In the SURMOUNT-5 trial, published in the New England Journal of Medicine (2025), tirzepatide produced greater average weight reduction than semaglutide 2.4mg over 72 weeks in a head-to-head comparison of adults with obesity and no diabetes. At the 15mg maintenance dose, average body-weight reduction in the SURMOUNT programme reached around 20–21%. Those are clinical trial figures with specific participant groups (individual results vary) but they represent the strongest head-to-head data available for any two licensed weight-management medicines in the UK.

NICE recommended tirzepatide in Technology Appraisal TA1026 for adults with a BMI of 35 or above and at least one weight-related comorbidity, with lower BMI thresholds for certain ethnic backgrounds. It is also licensed privately for adults with a BMI of 30 or above, or 27 or above with a relevant condition. Comparing semaglutide substitutes more broadly can help frame where tirzepatide sits in that picture.

Oral semaglutide (Wegovy tablets): same ingredient, no injection

For people who want to stay on semaglutide but avoid injections, the Wegovy tablet is now a real option. The MHRA approved it on 11 June 2026, the first oral GLP-1 medicine licensed in the UK for weight management, and the UK was the first country in Europe to grant that approval. The active ingredient is identical to the injection; the formulation uses an absorption enhancer called SNAC to allow the medicine to work orally.

The dosing schedule is different from the injection: once daily tablets starting at 1.5mg, escalating through 4mg and 9mg to a 25mg maintenance dose, with at least a month at each level. The tablet must be taken first thing in the morning on an empty stomach with a small amount of plain water, then nothing else (no food, coffee or other oral medicines) for at least 30 minutes. Room-temperature storage makes it considerably more travel-friendly than either injection.

In the OASIS 4 phase-3 trial (64 weeks, 307 adults with obesity or overweight plus at least one weight-related condition), average weight loss was around 13.6% compared to about 2.4% on placebo, with around 16.6% among participants who stayed fully adherent. It is available on private prescription only at launch; NICE has not yet appraised it. More on the semaglutide molecule itself explains what the injection and the tablet share at a pharmacological level.

One practical note: the cost of Wegovy treatment differs between formats and providers, and the tablet is a newer product, confirm current availability at consultation.

Orlistat and what it doesn't share with GLP-1 medicines

Orlistat is occasionally mentioned as a substitute, so it deserves an honest comparison. It is a lipase inhibitor (it blocks absorption of roughly a third of the fat you eat) and is available both as a lower-strength pharmacy medicine and a higher-strength prescription version. It has no effect on appetite signalling, no GLP-1 or GIP action, and the average weight loss in clinical studies is substantially lower than either semaglutide or tirzepatide.

It's also associated with a distinctive set of gastrointestinal side effects (oily stools, urgency, leakage) that are directly tied to fat intake, making dietary adherence critical to tolerability. For some people, particularly those who cannot use injectable or oral GLP-1 medicines for medical reasons, it remains a reasonable option. But describing it as a like-for-like substitute for Wegovy would be misleading. It's a different category of medicine, for a different clinical situation.

If you're weighing up the full range of options, the weight-loss treatment overview on this site covers the licensed UK landscape, and the semaglutide information page addresses how the GLP-1 class compares at a higher level, including how to reconstitute semaglutide if you are using a vial-based format rather than a prefilled pen. Our clinical team reviews every consultation personally, the right substitute, if one is appropriate, is a decision made with you, not for you.

Ready to explore which option suits your situation? Start your free consultation and a GPhC-registered prescriber will review your details the same day.