Tirzepatide Trade Names: Which Brand Is Licensed in the UK?

Why the same drug has different trade names in different countries

Eli Lilly developed tirzepatide and chose distinct brand names for different regulatory markets, a standard pharmaceutical practice. The name a medicine is sold under depends on the marketing authorisation granted in each country, not on the chemistry. So the molecule is identical; the label changes at the border.

In the UK, the MHRA granted Mounjaro its marketing authorisation. That is the name under which the medicine was reviewed, licensed and referenced by NICE's appraisal of tirzepatide (TA1026). It is the name on every legitimate UK pen, on every UK prescription, and on the Patient Information Leaflet inside the box. There is no parallel UK licence for any other tirzepatide brand.

If you've searched around and found references to names other than Mounjaro, you're almost certainly looking at products licensed in different jurisdictions, or, more worryingly, unlicensed products. That distinction matters a great deal for safety, which is why it's worth being precise about what each name actually refers to, and our guide to tirzepatide names is a good place to start.

Zepbound: the US trade name for tirzepatide, and why it is not available in the UK

Zepbound is the brand name under which Eli Lilly markets tirzepatide in the United States, where it was approved by the FDA specifically for chronic weight management. It is not a UK product. No UK pharmacy (registered or otherwise) can legally dispense Zepbound, because the MHRA has not issued a UK marketing authorisation under that name. The product that exists here is Mounjaro.

This is more than a labelling technicality. UK-licensed medicines carry specific storage, handling and patient-information requirements verified by British regulators. A pen described as Zepbound and offered for sale in the UK falls outside that framework entirely. The full overview of tirzepatide on this site covers what the UK licence actually permits and what the clinical evidence shows.

If you see Zepbound listed on a UK website, treat it as a serious red flag. The MHRA has consistently warned that medicines sold online under unfamiliar names, or offered without a proper clinical assessment, carry real risks, including the possibility that what arrives is counterfeit. Report suspect sellers at the MHRA's Yellow Card scheme.

Other names you may have encountered, and what they refer to

Beyond Mounjaro and Zepbound, tirzepatide appeared under the working names LY3298176 and GIP/GLP-1 RA during its clinical development phase. These identifiers are common in trial literature, including the SURMOUNT-1 paper published in the New England Journal of Medicine. You might encounter them if you've been reading research directly. They have no commercial significance now that the medicine is licensed.

It's also worth knowing that a fuller breakdown of tirzepatide brand names by market is available if you want to see how regulatory approvals differ internationally. For a concise comparison of how the UK name relates to other identifiers, this page on tirzepatide's different names is a useful companion.

The NHS tirzepatide medicines page uses both the generic name and the Mounjaro brand interchangeably, another sign that, for UK clinical purposes, Mounjaro is the definitive reference point. Everything on this site, including our prescribers' clinical assessments, operates within that framework.

What this means if you're considering treatment

If Mounjaro is the medicine you're interested in, knowing the trade-name landscape helps you avoid a category of risk that is genuinely serious. Counterfeit and unlicensed weight-loss pens have entered the UK market, some containing the wrong substance entirely. The MHRA's advice is straightforward: only obtain prescription medicines through a pharmacy you can verify on the GPhC register.

That's the kind of thing our prescribers field most weeks: patients who found a cheaper listing abroad or on social media and want to know if it's the same thing. Often it claims to be. Often the answer is: we can't verify it, and neither can you. The cost context for Mounjaro in the UK explains what a private prescription realistically includes, and why price alone is not a reliable signal of legitimacy.

At nume, our GPhC-registered pharmacy sources tirzepatide through the licensed UK supply chain. A named prescriber, not software, reads your consultation the same day. If Mounjaro is clinically suitable for you, treatment can be dispatched the same day you're approved. For a broader look at weight-loss treatment options or to begin a free consultation, our prescribers are available seven days a week.