Retatrutide is the drug people keep hearing about. This article is here to explain what it actually is, what the evidence currently shows, and, most importantly, why buying it from an online seller is a bad idea. Retatrutide is not licensed in the UK and is not available from Solira.
What retatrutide is
Retatrutide is an investigational medicine being developed by Eli Lilly. Where Mounjaro (tirzepatide) is a dual agonist acting on GLP-1 and GIP receptors, retatrutide is a triple agonist. It adds activity at the glucagon receptor. The theory is that glucagon receptor activity increases energy expenditure alongside the appetite suppression provided by the other two mechanisms.
Its licensing status in the UK
This needs to be said plainly: retatrutide is not licensed by the MHRA. It is not approved for use, it cannot be lawfully prescribed as a licensed medicine in the UK, and it is not available from any UK pharmacy, including through Solira. Retatrutide is still being studied in phase 3 trials, the first of which have now reported, but it is not licensed in the UK and no approval date has been set.
What the trial data shows so far
Phase 2 trial results published in the New England Journal of Medicine in 2023 reported substantial weight loss at higher doses over 48 weeks. That is why retatrutide has attracted so much attention.
It's worth being careful with what that actually means. Phase 2 results are early, involve relatively small numbers of participants, and are designed to establish signal and dose range, not to confirm long-term efficacy or safety. Phase 3 trials are required before any regulator will consider approval, and many drugs with promising phase 2 data do not reach approval.
Why you should not buy retatrutide online
This is the most important section of this article. If you are searching for retatrutide, you will find people offering to sell it. Do not buy it. Here is why:
- Products sold online as retatrutide are typically marketed as "research chemicals" or "not for human consumption". This is a deliberate legal evasion, a way to sell an unlicensed medicine without falling under medicines regulation.
- They are manufactured outside any regulated pharmaceutical supply chain, with no guarantee of identity, purity, sterility or dose. What is in the vial may not be what is on the label.
- There is no pharmacovigilance. If something goes wrong, there is no recall mechanism, no batch trace, and no one to report a serious reaction to.
- Dosing information circulating in online communities is not clinically validated. It is anecdote, not evidence.
- Injecting an unregulated peptide of unknown concentration carries real risk of infection, contamination and dosing error, including serious harm.
- A UK pharmacy cannot lawfully supply retatrutide. Any seller claiming otherwise is not operating within UK medicines law.
What you can actually get in the UK right now
If retatrutide caught your attention because of the weight loss figures, it's worth putting those numbers next to what's already licensed and available. The gap is smaller than the headlines suggest, and one side of the comparison has completed phase 3 trials, carries regulatory approval, and can be dispensed by a UK pharmacy today.
| Treatment | Average weight loss in trials | Trial stage | Available in the UK? |
|---|---|---|---|
| Retatrutide (triple agonist) | Not licensed, so we do not quote its trial results | Phase 3 trials under way; the first results are now being published | No, not MHRA licensed |
| Mounjaro / tirzepatide (dual agonist) | About 21% on 15mg over 72 weeks, counting everyone who started (SURMOUNT-1) | Phase 3 complete, licensed | Yes |
| Wegovy / semaglutide (GLP-1 agonist) | Around 15% at 2.4mg over 68 weeks (STEP-1), and 18.7% at 7.2mg over 72 weeks (STEP UP), counting everyone who started | Phase 3 complete, licensed | Yes |
Retatrutide is not licensed, so we give no figures for it: early trial results often change in larger studies, and an unlicensed medicine has no approved dose. Of the licensed medicines, tirzepatide and semaglutide have been compared directly in SURMOUNT-5, where people lost an average of 20.2% of their body weight on tirzepatide against 13.7% on semaglutide.
Are you eligible?
Licensed GLP-1 treatment is available in the UK if you meet the clinical criteria. Broadly, that means:
- A BMI of 30 or above, or
- A BMI of 27 or above alongside a weight-related condition such as high blood pressure, type 2 diabetes, high cholesterol or obstructive sleep apnoea
- You must be 18 or over and not pregnant or breastfeeding. Some conditions, such as previous pancreatitis or a personal or family history of medullary thyroid cancer, mean we will not supply treatment.
Eligibility is confirmed through a consultation reviewed by a pharmacist, not by a form. If you are not suitable, we will tell you and explain why.
Check if you're eligible. Free online consultation, reviewed by a GPhC-registered pharmacist. No obligation and no consultation fee.
Check my eligibilityWhen might retatrutide be available?
Honestly: no one knows. Retatrutide is still being studied in phase 3 trials, the first of which have now reported, but it is not licensed in the UK and no approval date has been set. Any UK availability would require MHRA approval, which has not happened. Anyone giving you a confident date is guessing.
The people selling "retatrutide" online are not offering early access to a promising new medicine. They are selling an unregulated peptide of unknown quality, outside medicines law, with no safety net if something goes wrong.