Is Mounjaro and Tirzepatide the Same Thing?

Step 1: understanding why two names exist for one medicine

Every medicine approved for use in the UK has at least two names: an international nonproprietary name (INN) (the generic, scientific name that regulators and pharmacists use) and a brand name chosen by the manufacturer. Tirzepatide is the INN. Mounjaro is Eli Lilly's brand. This naming convention is entirely routine: semaglutide is the INN for Wegovy and Ozempic, for example, just as paracetamol sits inside branded products from dozens of different companies.

In practice, a doctor or prescriber writing a private prescription may write either "tirzepatide" or "Mounjaro", both refer to the same pre-filled KwikPen containing the same molecule at the same strength. You'll find a fuller breakdown of what that molecule actually does in the body on the tirzepatide overview page.

One nuance worth knowing: in the UK, tirzepatide is currently only available under the Mounjaro brand. There is no separately licensed generic tirzepatide product on the UK market at the time of writing. So the names are interchangeable in practice, but Mounjaro is the only physical product a UK pharmacy can legally dispense for weight management.

Step 2: what tirzepatide actually does, and why it's different from other weight-loss medicines

Tirzepatide (sold as Mounjaro) works by activating two gut-hormone receptors simultaneously: GIP (glucose-dependent insulinotropic polypeptide) and GLP-1 (glucagon-like peptide-1). That dual action sets it apart from semaglutide, which acts on GLP-1 alone. Both pathways are involved in appetite regulation, slowing the rate at which the stomach empties and signalling fullness to the brain. Activating both at once appears to produce a stronger overall effect, which the SURMOUNT-1 trial, published in the New England Journal of Medicine, reflected in its results: participants at the 15 mg dose saw an average body-weight reduction of around 20–21% over 72 weeks.

If you're curious whether GLP-1 activity alone explains tirzepatide's effects, the short answer is no, the GIP component adds meaningfully to the outcome. The differences between GLP-1 agonists and tirzepatide's dual mechanism are covered in detail elsewhere, but the headline is that Mounjaro is the only approved weight-loss medicine in the UK working on both receptors.

The NHS patient information page for tirzepatide on nhs.uk uses both names throughout, further confirmation that they describe the same thing.

Step 3: what the UK licence covers and who it's for

Mounjaro (tirzepatide) holds a UK marketing authorisation for two separate purposes: weight management in adults, and the management of type 2 diabetes. For weight management, the licence covers adults with a BMI of 30 or above, or a BMI of 27 or above alongside at least one weight-related health condition such as high blood pressure, high cholesterol, obstructive sleep apnoea or prediabetes. Lower BMI thresholds can apply for certain ethnic backgrounds under NICE guidance TA1026.

A BMI figure alone doesn't determine whether Mounjaro is appropriate for a specific person. A prescriber will look at the full picture: current health conditions, any medicines that might interact, and whether there are any reasons the medicine shouldn't be used, for instance, a personal or family history of medullary thyroid carcinoma or MEN2. Mounjaro is not licensed for use during pregnancy, breastfeeding or when trying to conceive, and it is not authorised for people under 18. If you have questions about specific conditions and how they interact with treatment, our guide to tirzepatide and idiopathic intracranial hypertension is one example of the condition-specific detail we cover.

If you've seen references to "Manjaro" rather than Mounjaro, that's simply a spelling variation that appears frequently online, there is no medicine called Manjaro; the brand name is always Mounjaro.

For a detailed look at how private treatment pricing works in the UK, the Mounjaro cost page covers what a private prescription typically includes and what to watch for when comparing providers.

Step 4: what to expect if you're considering treatment

Because Mounjaro is a prescription-only medicine, the legal route in the UK runs through a clinical assessment with a registered prescriber. Self-diagnosing eligibility from a name search is a reasonable start, but it's the prescriber's job to make the actual decision. A question our prescribers field most weeks is whether a patient who read about "tirzepatide" online and a friend who was prescribed "Mounjaro" are actually talking about the same treatment. They are.

At nume, every consultation is read by a GPhC-registered Independent Prescriber (a real clinician, not a decision tree) on the same day it arrives. Identity is verified, weight is confirmed on video, and where relevant the prescriber checks your Summary Care Record before any decision is made. Treatment, if approved, is dispatched the same day for free next-working-day delivery via DPD. Orders placed before 12pm on a working day go out that afternoon, which matters if you're planning around a Monday start or returning from a holiday break. There are no subscriptions; every repeat order goes through a fresh clinical review.

If you'd like to understand the full scope of what a Mounjaro prescription through a regulated UK pharmacy involves, the Mounjaro treatment page covers the detail. Or, if you're ready to find out whether you're clinically suitable, check your eligibility with a free consultation.