Semaglutide Biosimilars: What the UK Decision Means for You

What a biosimilar actually is, and why semaglutide is a harder case than most

Generic medicines and biosimilars are often discussed as though they are the same thing. They are not. A conventional generic is a chemically identical copy of a small-molecule drug, relatively straightforward to manufacture and test. A biosimilar is a near-copy of a biologic medicine, which means it is derived from living cells and has a complex three-dimensional structure that cannot simply be replicated from a formula.

Semaglutide is a biological medicine: a modified GLP-1 receptor agonist peptide. Reproducing it to a sufficient standard requires extensive analytical work, and regulators (including the MHRA) require a dedicated clinical and non-clinical dossier before granting approval. This is not a rubber-stamp process. It typically takes several years from a manufacturer's application to a licensing decision. Calling something a "semaglutide biosimilar" does not make it one in the eyes of UK law, and several products sold online under that description carry no MHRA authorisation at all, including products sometimes marketed as sigma semaglutide, which has no UK marketing authorisation.

You can check whether any medicine holds a UK marketing authorisation in under a minute by searching the MHRA's products register or the electronic Medicines Compendium at medicines.org.uk. If a product is not listed there, it has not been assessed by the regulator. That is the practical habit worth building before you buy anything described as a semaglutide alternative online. The NHS medicines page for semaglutide is also a clear starting point for understanding what is and is not a recognised product.

Why unlicensed "biosimilars" appearing online are a genuine risk, not a technicality

The MHRA has been explicit about the danger here. In October 2023 it issued warnings about counterfeit weight-loss pens circulating online, some contained insulin rather than the labelled medicine, and hospitalisations followed. Since then, enforcement has continued to escalate: in late 2025 the MHRA raided the first illicit UK manufacturing site producing counterfeit tirzepatide pens. The pattern is consistent: unlicensed products sold through social media, messaging apps and unofficial websites, often at prices that seem too good to be true, and often described using credible-sounding terms like "biosimilar" or "compounded semaglutide".

None of this is to suggest that the concept of biosimilar competition is bad, in many therapeutic areas, approved biosimilars improve patient access. The concern is specifically about products that use the biosimilar label to circumvent the licensing process. If a seller cannot point you to a UK marketing authorisation number, that is a significant red flag. Reporting suspect sellers is straightforward through the MHRA Yellow Card scheme, which also accepts reports about suspected counterfeit medicines.

For anyone researching medicines similar to semaglutide for weight loss, the relevant question is not whether an unlicensed version exists somewhere, it is whether a licensed one is right for you clinically. That is a different and more useful question.

What the landscape looks like right now, and what might change

The patent situation around semaglutide is active and contested globally. In some countries outside the UK, compounded semaglutide has been permitted under specific shortage provisions (this has been the case in the United States) but those provisions do not apply in the UK, and UK compounding law does not permit the routine preparation of a licensed medicine like Wegovy for commercial supply. The regulatory context here is distinct.

Looking ahead, it is plausible that biosimilar applications will be submitted to the MHRA as Novo Nordisk's relevant patents expire. If and when an application receives approval, that would be a significant licensing event and would be reported through official MHRA channels. Until then, the only licensed semaglutide product for weight management in the UK is Wegovy. For a cost comparison of what legitimate private treatment involves, the guide to Wegovy pricing in the UK lays out the market context honestly. And for a broader look at medicines related to semaglutide, there is more detail worth reading before making any decision.

The practical decision you are actually facing

If you have arrived at the biosimilar question, you are probably asking it for one of two reasons: cost, or curiosity about whether a cheaper alternative exists. Both are completely reasonable. The honest answer is that cost is a real consideration for many people, and the absence of authorised biosimilars in the UK means there is no licensed lower-cost version available right now.

What does exist is a licensed treatment (Wegovy) that can be accessed privately through a GPhC-registered pharmacy following a clinical assessment, without a GP referral or an NHS waiting list. At nume, that assessment is carried out personally by a GPhC-registered Independent Prescriber, not automated software, on the same day you complete your consultation. Your clinical team can also talk through whether Wegovy or another licensed weight-loss treatment is the better fit for your circumstances. That is the kind of decision worth making with a prescriber rather than working out alone. If you are ready to take that step, you can start your free consultation today.