LY3437943
A substance under study that mimics three hormones linked to appetite and blood sugar. Not approved in the EU or US.
This site is for information and education only. It does not promote or encourage the use or purchase of the substances described and is not medical advice. Many are not authorised as medicines and their safety has not been established. We sell nothing and have no ties to sellers. For health decisions, consult a doctor.
Doping. It is not on the WADA list, but WADA also bans substances that no health authority has approved, so it may be banned.
Safety. There are early results and the first large studies. Pulse rose, most of all around week 24. A 2026 case report describes constant nausea after injecting a product said to contain retatrutide. There is no approval and no follow-up over many years. Sources: study 1, study 2, study 3.
Risk of fakes. No medicine is approved, so everything on sale lacks approval. The group Public Citizen reports hospital stays and gaps in oversight. Sources: Public Citizen, study 1.
| Where | Status | Checked | |
|---|---|---|---|
| PL | No approval | The European medicines database (EMA) lists no such medicine in Poland (9 October 2026). The Polish register was down, so we could not check it directly. Source | Not yet |
| EU | No approval | The European medicines database (EMA), which covers EU and national approvals, lists no such medicine (9 October 2026). Source | Not yet |
| US | No approval | The FDA drug register has no such medicine. Source | Not yet |
Scientific papers per year 2015–2025
These are search results. A count shows how much exists, not how good the studies are. 1 Nov 2026.
Effect in studies. Early and large studies show big weight loss: 18.8% at the highest dose and 5.1% on placebo, in adults with diabetes. No medicine is approved yet, and this grade says nothing about products sold online.
What doctors, patients and companies reported to the US medicines agency (FDA), and single cases described in medical journals. A report says what happened to someone after taking the substance. It does not prove the substance caused it, and it does not say how often it happens. Reports do not change any grade.
| Most often reported | Reports |
|---|---|
| Vomiting | 13 |
| Nausea | 11 |
| Tiredness | 6 |
| Stomach pain | 5 |
| Fast heartbeat | 5 |
| Dizziness | 4 |
| Shortness of breath | 4 |
| Feeling unwell or strange | 4 |
Serious means the person went to hospital, their life was in danger, they were left with lasting harm, or they died. One report can list several side effects.
FDA reports come from openFDA, cases from a PubMed search. The editors have not read these cases yet. Titles stay in the original language. As of 3 Nov 2026.
A short video in which the author rates popular peptides on a scale from S to F. His ratings are an opinion on whether something is worth taking. Our grades from A to E only say how strong the studies are. The comparison below is based on the video description.
A bodybuilder with a biochemistry degree goes through peptides for weight loss, injury healing and longevity: what works, what the risks are and where studies are missing. The description lists his sources, mostly large studies of semaglutide and tirzepatide.
The description has ads
The author describes her sixth week on retatrutide: weight, side effects and appetite. She notes herself that it is a medicine still in trials and that she recommends nothing.
One person, no comparison group, and nobody knows what was in the product.
The author took retatrutide outside of trials for 6 months and then stopped. He says he lost 25 lb, of which 10 lb was muscle according to a body scan (DEXA), and describes a reaction with a heartburn medicine that he says nearly put him in hospital.
One person, no comparison group, and nobody knows what was in the product.
The video talks about doses or buying. We do not repeat them.
| Studies | Kind of study | Who was studied | People | Duration | Dose as studied | Who paid |
|---|---|---|---|---|---|---|
| Retatrutide in adults with obesity and type 2 diabetes (TRIUMPH-2): a double-blind, parallel-group, randomised, placebo-controlled, phase 3 trial. | Random groups | Adults with obesity and type 2 diabetes, phase 3 (TRIUMPH-2) | – | 80 wk | 4, 9 or 12 mg weekly | Manufacturer |
| Effects of retatrutide on body composition in people with type 2 diabetes: a substudy of a phase 2, double-blind, parallel-group, placebo-controlled, randomised trial. | Random groups | Adults with type 2 diabetes, body composition substudy | – | 36 wk | 0.5 to 12 mg weekly | Manufacturer |
| Triple-Hormone-Receptor Agonist Retatrutide for Obesity - A Phase 2 Trial. | Random groups | Adults with obesity, phase 2 | – | 48 wk | 1 to 12 mg weekly | Manufacturer |
We found these papers automatically in PubMed. The editors have not read them yet, and they do not affect any grade. Titles stay in the original language.
