How Long Has Mounjaro Been Around?

Tirzepatide is a dual GIP and GLP-1 receptor agonist developed by Eli Lilly. Research into the GLP-1 pathway — the mechanism shared by both Mounjaro and Wegovy — stretches back to the 1980s and 1990s, when scientists first identified the hormone's role in appetite regulation and blood-sugar management. That foundational work took decades to translate into approved medicines.

From diabetes research to weight management

Mounjaro was first studied and authorised for the management of type 2 diabetes. Large clinical trials — collectively known as the SURPASS programme — evaluated tirzepatide in adults with type 2 diabetes across multiple countries, with results published between 2021 and 2023. These trials ran for periods of up to 40 weeks in the core studies, with longer-term extension data also collected. Authorisation for weight management (under the brand name Mounjaro in many markets) followed later, supported by a separate clinical programme called SURMOUNT.

How long has Mounjaro been used for diabetes?

In the United States, tirzepatide was first approved for type 2 diabetes in mid-2022. European and UK approvals for both the diabetes and weight-management indications followed in 2023. So while the medicine is still relatively new to general clinical practice, it is backed by several years of structured trial data involving tens of thousands of participants.

How does Mounjaro compare to Wegovy in terms of history?

Wegovy (semaglutide for weight management) received its first regulatory approval slightly earlier than Mounjaro — in 2021 in some markets and 2023 in the UK. Semaglutide itself, the active substance in Wegovy, had already been used in diabetes treatment for several years before the higher-dose weight-management formulation was authorised. If you are curious about how long Wegovy takes to work once started, that is a separate question from its regulatory history. Both medicines belong to the GLP-1 class, and weight-loss injections using this mechanism have been an active area of research for well over a decade.

For a broader look at the mechanism behind these medicines, see our guide to how Mounjaro works. If you want to understand the practical side of timing — such as how long Mounjaro takes to work after starting — that covers what to expect in the early weeks.

Knowing that Mounjaro is a relatively new medicine makes consistent tracking even more valuable — both for your own understanding and for informative conversations with your prescriber.

The most relevant feature for this is GLP Trackr's insights and analytics. As you log each week's injection, weight, and how you feel, the app builds a picture of your personal journey over time — a daily brief, week-at-a-glance summaries, and correlation data that shows how factors like sleep, protein intake, and activity relate to your results. Because this is a newer class of medicines, your own logged data is genuinely useful context to bring to prescriber appointments.

The app's dose and injection logging also helps you keep a clear, timestamped record of every shot — especially helpful during the titration phase when your prescriber may be reviewing how you are responding. You can also explore what the early weeks on Mounjaro typically look like to understand what your logs might show.

GLP Trackr supports people prescribed both Mounjaro and Wegovy — wherever in the world you are taking it and however far into your journey you are. The app is available free on the App Store and Google Play, with a 7-day trial so you can explore every feature before committing. Start logging from your very first dose and let the data tell your story.

GLP Trackr is an informational tracking tool, not a clinical service. Any questions about how Mounjaro or its history relates to your own treatment should be directed to your prescriber or doctor — they are best placed to advise based on your full medical history.