Digestive & weight Triple GLP-1 / GIP / glucagon agonist
Retatrutide
Regulatory status
Status at a glance
503A compounding status
Not nominated
We found no pending nomination for the 503A bulks list. Unless the substance has another legal pathway (for example, a USP monograph or use in an FDA-approved drug), 503A pharmacies generally may not compound with it.
- FDA approval
- Not FDA-approved for any use
- 503B outsourcing
- Not determined
- Anti-doping (WADA)
- Not on the WADA Prohibited List
- DEA schedule
- Not a controlled substance
About peptide status
Most peptides discussed here are not FDA-approved for any use, and products labeled “research use only” are not for human use. Removal from Category 2 does not authorize compounding. PCAC votes are non-binding recommendations; FDA and HHS make the final decisions.
This is not medical or legal advice, and we do not publish dosing, sourcing or reconstitution information. Talk with a licensed clinician before using any peptide.
If you think you are having a medical emergency, call 911.
Key takeaway
Retatrutide is an investigational "triple agonist" that activates the GLP-1, GIP, and glucagon receptors, developed by Eli Lilly as a once-weekly injection for obesity, type 2 diabetes, and liver disease. In Phase 2 and Phase 3 trials it produced large, consistent weight reductions, and a Phase 2 substudy reported liver-fat reductions of more than 80% at 24 weeks. As of 2026 it is not yet approved, with an FDA filing targeted for 2027.
At a glance
- FDA status
- Investigational peptide, not yet approved by the FDA
- How it works
- Activates three receptors: GLP-1, GIP, and glucagon
- Research
- Large, consistent Phase 3 weight-loss data in obesity, plus supportive liver-fat results
- FDA filing
- Eli Lilly has said it plans to file in 2027
- Evidence strength
- Deep research
Summary
Retatrutide is an investigational triple agonist of the GLP-1, GIP, and glucagon receptors. Learn how it works, what trials show, and where FDA approval stands.
What is retatrutide?
Retatrutide is an experimental drug that activates three hormone receptors in a single molecule: GLP-1, GIP, and glucagon (sometimes called a "triple-G" agonist). It is being developed by Eli Lilly under the code LY3437943 as a once-weekly injection for obesity, type 2 diabetes, and related conditions including fatty liver disease. It is investigational and not yet approved.
How does it work?
Retatrutide combines three hormone actions. The GLP-1 and GIP receptors are incretin targets whose activation enhances glucose-dependent insulin release and reduces appetite. The third target, the glucagon receptor, is the distinguishing feature: activating it is thought to increase energy expenditure and mobilize fat from the liver.
The idea is that adding glucagon action to the two incretin effects boosts weight loss and reduces liver fat beyond what incretin-only drugs achieve. This describes the proposed mechanism, which the trials below are designed to test.
Is it FDA-approved?
Safety note
Status: Investigational peptide, not yet approved by the FDA
Category: In clinical trials · Primary body area: Digestive & weight
No. Retatrutide is investigational and not approved. According to Eli Lilly, following positive Phase 3 readouts the company plans to file with the FDA in 2027, a timeline it has attributed partly to manufacturing and quality verification.
What does the research show?
Editor’s note
Evidence strength: Deep research (4 human · 0 animal/cell studies)
It has strong, consistent, replicated Phase 3 weight-loss evidence plus supportive Phase 2 and liver-fat data, but it is not FDA-approved.
The evidence spans large, consistent trials. According to PubMed, the Phase 2 trials and the Phase 3 program reported these results:
| Study | Reported result |
|---|---|
| 48-week Phase 2 trial in obesity | Mean weight loss of around 24% at the highest dose versus about 2% with placebo |
| Phase 2 liver-fat substudy | Reductions in liver fat of more than 80% at 24 weeks |
| Phase 3 TRIUMPH-1 in obesity without diabetes | Mean weight loss of roughly 24-25% at the higher doses over 80 weeks |
| Phase 3 TRIUMPH-2 in obesity with type 2 diabetes | Roughly 17-19% weight loss, with improved blood sugar |
Gastrointestinal effects were the most common side effects and were dose-related. These results are consistent across replicated trials, though the drug is not yet approved.
Sources: the Phase 2 obesity trial (Jastreboff et al., New England Journal of Medicine, 2023, DOI: 10.1056/NEJMoa2301972); the Phase 2 liver-fat substudy (Sanyal et al., Nature Medicine, 2024, DOI: 10.1038/s41591-024-03018-2); TRIUMPH-1 (Jastreboff et al., New England Journal of Medicine, 2026, DOI: 10.1056/NEJMoa2604169); and TRIUMPH-2 (Bellido et al., The Lancet, 2026, DOI: 10.1016/S0140-6736(26)01861-1), all indexed on PubMed. This document is educational, is not medical advice or a health claim, and is not an offer to sell any product.
Registered human trials
4 registered human trials on ClinicalTrials.gov that we reviewed
Sources
- [1]
- [2]
- [3]
- [4]
- [5]
- [6]
- [7]
- [8]
- [9]
- [10]
- [11]
Compare every peptide’s status in the peptide regulatory status database
More for Digestive & weight
View all digestive & weight peptides →- Not FDA-approved Digestive & weight
5-Amino-1MQ
5-Amino-1MQ is a small-molecule NNMT inhibitor that, in cell studies, increases NAD+ and SAM and suppresses fat production in fat cells. In diet-induced obese mice, a potent NNMT inhibitor reduced body weight and fat mass without changing food intake. As of 2026, no human trials have been published, and it is not a peptide. It is not approved by the FDA.
- In clinical trials Digestive & weight
Amycretin
Amycretin is an investigational single-molecule drug that activates both the GLP-1 receptor and the amylin receptor, being developed by Novo Nordisk in subcutaneous and oral forms for weight management. In a 2025 phase 1b/2a trial of 125 adults with overweight or obesity, the 60 mg group lost 24.3% of body weight at 36 weeks versus 1.1% on placebo (p < 0.0001), though many participants withdrew. As of 2026 it is not approved anywhere and is moving into Phase 3 testing.
- Not FDA-approved Digestive & weight
Aod-9604
AOD-9604 is a modified fragment of the tail end of human growth hormone, developed as a fat-loss drug. Its human obesity trials failed to beat placebo, and development for obesity was halted. As of 2026 it is not FDA-approved and is banned in sport.
- In clinical trials Digestive & weight
Apraglutide
Apraglutide is an investigational long-acting GLP-2 analog, developed by Ironwood Pharmaceuticals as a once-weekly injection for short bowel syndrome, a condition in which people depend on intravenous nutrition because their intestine cannot absorb enough. In a Phase 3 trial it reduced the need for that intravenous support compared with placebo. As of 2026 it is not approved, and the FDA has asked for an additional confirmatory trial.
- Not FDA-approved Digestive & weight
Bpc-157
BPC-157 is a synthetic 15-amino-acid peptide studied for tissue and gut repair, and 35 of the 36 studies in a 2025 systematic review were animal or lab work. The one human report, a retrospective series of 12 patients with chronic knee pain, found that seven (58%) described relief lasting more than 6 months. It had no control group, effect size, or safety data. BPC-157 is not FDA-approved, is prohibited in sport, and remains unsettled in FDA compounding review.
- In clinical trials Digestive & weight
Brilacidin
Brilacidin is an investigational defensin-mimetic, a small molecule designed to imitate the body's own host-defense peptides, developed by Innovation Pharmaceuticals for oral mucositis and studied as an antibacterial and antiviral agent. Its human results to date have been reported mainly through company announcements rather than peer-reviewed trials, while published support is largely laboratory-based. As of 2026 it is not approved for any use.