Does Ozempic Contain Tirzepatide? The Active Ingredients Explained

Semaglutide and tirzepatide: what each one actually does

The fastest way to clear up the confusion is to start with the regulatory record. Ozempic is a brand of semaglutide — a GLP-1 receptor agonist licensed in the UK for type 2 diabetes, not for weight management. That licensing point matters: the NHS medicines page for semaglutide covers both Ozempic and Wegovy, but makes clear that Wegovy (also semaglutide, at the 2.4mg weekly dose) is the formulation licensed for weight loss. Using Ozempic off-label for weight reduction is not the same thing, and it is not available from a regulated weight-loss service in the UK for that purpose.

Tirzepatide, sold as Mounjaro, is an entirely different compound. It activates both the GLP-1 and GIP receptors, the only dual-agonist licensed for weight management in the UK. That dual action is the main reason it appears in a different column of every comparison table. If you want to understand the molecular distinction in more depth, the page on whether Ozempic is tirzepatide or semaglutide goes further into the pharmacology.

Neither medicine should be running loose in a gym bag without proper storage: both require refrigeration between 2°C and 8°C, with a limited window at room temperature detailed in each medicine's Patient Information Leaflet.

Head-to-head trial data: what SURMOUNT-5 found

For years the comparison between semaglutide and tirzepatide relied on indirect estimates, the trials used different populations, different designs and different durations. That changed with SURMOUNT-5, an open-label, randomised trial of 751 adults with obesity and no diabetes, published in the New England Journal of Medicine in 2025. Over 72 weeks, participants on tirzepatide (at the highest tolerated dose up to 15mg weekly) achieved greater average weight reduction than those on semaglutide 2.4mg. The SURMOUNT-1 trial had already shown tirzepatide produced around 20–21% average body-weight reduction at 15mg over 72 weeks. NICE's technology appraisal of tirzepatide (TA1026) cited this evidence in recommending it for NHS use in eligible adults.

Semaglutide's phase-3 data, from the STEP 1 trial, showed around 15% average weight loss over 68 weeks at the 2.4mg dose. The gap between the two narrows at semaglutide's newer 7.2mg maintenance dose, the MHRA approved a dedicated single-dose 7.2mg Wegovy pen in April 2026, with trial data reporting approximately 20.7% average loss over 72 weeks. Whether that closes the practical difference for an individual patient is a clinical question, not a headline one.

The Wegovy vs Mounjaro comparison walks through the trial evidence in more detail, including the SURMOUNT-5 results in full context.

UK licensing: what each medicine is legally approved for

Sources: NHS tirzepatide medicines page; MHRA licensing records.

The table makes one thing plain: Ozempic is not interchangeable with either Wegovy or Mounjaro for weight management. A regulated UK pharmacy will not dispense Ozempic for weight loss, and an online seller offering it for that purpose is a warning sign worth taking seriously. The MHRA has warned repeatedly about fake weight-loss pens and unlicensed sellers; the Yellow Card reporting scheme is where suspicious products should be reported.

For anyone asking a related question, people who want to know whether tirzepatide works in a similar way to Ozempic will find that covered separately, as will those curious about whether Ozempic can be considered a tirzepatide. The page on whether tirzepatide is the same as Ozempic takes that specific angle.

What this means if you are considering treatment

If weight management is the goal, the two licensed injectable options in the UK are Wegovy (semaglutide) and Mounjaro (tirzepatide). Both require a prescription following a clinical assessment, eligibility depends on BMI, weight-related health conditions and a full medical review, not just a number on a scale. NICE recommends tirzepatide (TA1026) for adults with BMI ≥35 plus at least one weight-related comorbidity; lower thresholds apply for some ethnic backgrounds under UK guidance. Wegovy is recommended under TA875 within specialist weight management services, for a maximum of two years. Private treatment through a regulated pharmacy like nume sits alongside those pathways for people who don't meet NHS criteria or prefer not to wait.

Which medicine suits a particular person (given their health history, existing medicines and preferences) is exactly the kind of question a prescriber works through with them. It is not a decision that can be made on the basis of trial averages alone. You can explore both options on the treatment options page, or read a fuller breakdown of how Wegovy and Mounjaro compare in practice before speaking to a prescriber.