Not yet available — in clinical trials
Retatrutide
An investigational weekly injection from Eli Lilly, the maker of Mounjaro, that's shown the strongest average trial results of any weight-loss drug so far — but it isn't approved anywhere in the UK yet, and can't legally be prescribed or sold.
Quick Facts
- Weight Loss — triple agonist — in clinical trials
- Not yet available in the UK
- No providers can legally offer this yet
- Content last reviewed 13 August 2026
This page provides general information, not medical advice — whether any treatment is right for you is a decision for a UK-registered prescriber after reviewing your individual history.
What it is
Retatrutide is an experimental medicine that acts on three separate gut and pancreatic hormone receptors at once — GLP-1, GIP, and glucagon — rather than the one or two that existing licensed treatments target. That third mechanism, glucagon receptor activity, is thought to help the body burn more stored fat for energy on top of the appetite-suppressing effects shared with Mounjaro and Wegovy. It's still going through clinical trials, run by Eli Lilly, the same company that makes Mounjaro, and has not been reviewed or approved by the MHRA or any other UK regulator.
How the clinical trials have gone so far
In the Phase 2 trial, published in the New England Journal of Medicine, participants on the highest weekly dose lost an average of roughly a quarter of their starting body weight over 48 weeks. Eli Lilly's own Phase 3 announcement reported an average loss of around 28.7% of starting body weight over 68 weeks in the headline trial — the strongest published average for any GLP-1-class medicine so far, though trial averages don't always translate directly into real-world results once a drug reaches general use.
Retatrutide vs Mounjaro vs Wegovy
Trial results come from different studies with different designs and populations, so these figures aren't a direct head-to-head comparison.
When might it be available in the UK?
Phase 3 trials need to complete before Eli Lilly can apply for approval, and the MHRA then reviews the full safety and efficacy data before any UK licence is granted. Realistically, that puts legal UK availability past 2027 even on an optimistic timeline.
What's promising, and what's still unknown
What's promising so far
- Phase 3 trial data released by Eli Lilly reported an average weight loss of around 28.7% of starting body weight over 68 weeks, the strongest headline figure of any GLP-1-class drug published to date
- Once-weekly self-injection, consistent with how Mounjaro and Wegovy are already dosed
- Comes from the same manufacturer and trial infrastructure behind Mounjaro, which is already licensed and established in the UK
Why you can't get it yet
- Not approved or licensed anywhere in the UK — it cannot legally be prescribed or sold by any provider, including every provider listed on this site
- Long-term safety data is still limited, since Phase 3 trials are ongoing
- No confirmed dosing schedule, price, or availability date — anything you read, including on this page, is based on trial data, not a finished product
- Realistically unlikely to be legally available in the UK before 2027, even on an optimistic approval timeline
Who this page is for
Nobody, yet — this page exists so you can understand what retatrutide is and how the research is progressing while you wait, not to help you obtain it. If you're considering weight loss treatment now, our other weight loss treatment comparisons cover what's actually licensed and available today.
Availability
Not yet available — still in clinical trials, no confirmed UK price.
Where you can't get it
Frequently asked questions
What is Retatrutide?
Retatrutide is an experimental medicine that acts on three separate gut and pancreatic hormone receptors at once — GLP-1, GIP, and glucagon — rather than the one or two that existing licensed treatments target. That third mechanism, glucagon receptor activity, is thought to help the body burn more stored fat for energy on top of the appetite-suppressing effects shared with Mounjaro and Wegovy.
How much does Retatrutide cost in the UK?
Retatrutide is not yet available in the UK and does not have a price, since it cannot legally be prescribed or sold while still in clinical trials.
Who is Retatrutide best suited to?
Nobody, yet — this page exists so you can understand what retatrutide is and how the research is progressing while you wait, not to help you obtain it. If you're considering weight loss treatment now, our other weight loss treatment comparisons cover what's actually licensed and available today.
Sources
- Jastreboff AM, et al. Triple–Hormone-Receptor Agonist Retatrutide for Obesity — A Phase 2 Trial. New England Journal of Medicine, 2023.
- Eli Lilly and Company. Investor news release on Phase 3 retatrutide trial results.
- MHRA. News release on enforcement action against illicit weight-loss medicine production.
Want what's actually available now?
See the licensed weight loss options real UK providers can offer today.
PickMyClinic is an independent comparison site, not a pharmacy or clinic. This page is not a personal recommendation and does not replace advice from a UK-registered prescriber. Some links on this site may be affiliate links; see our Affiliate Disclosure.