How Wegovy Differs from Ozempic — and Why Getting This Wrong Has Consequences

The myth worth correcting first: they're not interchangeable

The single most common misconception about these two medicines is that because Ozempic and Wegovy both contain semaglutide, they can be swapped freely depending on whichever is in stock or cheaper. That is not how UK licensing works. The NHS medicines page for semaglutide is clear that the two products carry distinct authorisations, and the MHRA licenses each presentation for specific indications. Ozempic was authorised for blood-sugar control in adults with type 2 diabetes. Wegovy was authorised for weight management in adults with a BMI of 30 or above, or 27 or above with a weight-related condition such as high blood pressure or high cholesterol.

In practice this means a prescriber cannot simply offer Ozempic to someone who wants to lose weight and present it as routine care. Doing so would be an off-licence prescription requiring documented clinical justification. For the majority of people seeking treatment for their weight, Wegovy is the medicine whose licence actually covers their situation.

The confusion is understandable. Both are once-weekly subcutaneous injections. Both slow gastric emptying and reduce appetite through the GLP-1 pathway. The molecule is identical. But the dose, the trial evidence submitted for each licence, and the clinical population each product was approved for are not the same, and those differences matter when a prescriber is deciding what is appropriate for you.

Where the doses and the evidence actually diverge

Ozempic's standard maintenance doses in diabetes management reach 1 mg or 2 mg weekly. Wegovy's licensed maintenance dose is 2.4 mg weekly, reached by titrating from a 0.25 mg starting dose over approximately four months. In January 2026 the MHRA approved a 7.2 mg dose for Wegovy, and a dedicated single-dose 7.2 mg pen was authorised in April 2026 for adults with a BMI of 30 or above. You can read more about the evidence behind how these semaglutide medicines work and what the clinical trial data showed.

The weight-loss trials for Wegovy used the 2.4 mg dose specifically. The STEP 1 trial, published in the New England Journal of Medicine, found an average weight reduction of around 15% over 68 weeks at 2.4 mg. That evidence base was gathered at doses higher than those typically used for diabetes, which is why the licensing is not fungible. A diabetes-optimised dose of semaglutide in Ozempic was not tested at the same intensity for weight management, and it would not produce the same average outcome.

If you are curious whether switching between these products is possible in specific circumstances, our page on changing from Ozempic to Wegovy covers the clinical considerations in more detail.

What a prescriber can actually offer, and what this means for you

If your goal is weight management and you do not have a type 2 diabetes diagnosis, the medicines with a UK licence for that purpose are Wegovy and Mounjaro (tirzepatide). Ozempic has no weight-management licence in the UK, and the MHRA has stated explicitly that GLP-1 medicines are not assessed for quick or cosmetic weight loss. A responsible prescriber works within the licensed indications, not around them.

For a broader sense of your options, the treatment overview sets out what is currently available on prescription in the UK. If you have already been on Ozempic for diabetes and your circumstances have changed, a prescriber can discuss whether a transition is appropriate, moving from Ozempic to Wegovy is a question with a real clinical answer, not just a matter of preference.

One practical thing you can do in under a minute: check whether any pharmacy offering semaglutide for weight loss is registered on the GPhC pharmacy register. If it does not appear there, do not proceed. Genuine medicines dispensed through a registered pharmacy follow a licensing and prescribing process precisely because the distinction between these products has real safety implications. Our clinical team at nume, including our lead prescriber, review every consultation personally before any treatment is issued.

The NHS access question is separate for each medicine

Because Ozempic and Wegovy carry different licences, NHS access routes for each are entirely distinct. Ozempic is prescribed through standard diabetes pathways. Wegovy on the NHS is available through specialist weight management services under NICE's guidance (TA875), which specifies a maximum treatment duration of two years within a multidisciplinary service. Waiting lists for those services are commonly long across England. For people who are eligible for weight management treatment but do not want to wait, a private prescription through a regulated pharmacy is the practical alternative. You can find out more on the options for obtaining Wegovy through legitimate routes, or explore the semaglutide topic page for a fuller picture of how this medicine fits into UK weight management. If weight management is what you are looking for, speaking to a prescriber about the right medicine for your circumstances is always the right starting point. Speak to our prescribers through a free consultation, and a GPhC-registered Independent Prescriber will review your case the same day.