Retatrutide: News, Trial Results and FDA Status
Independent coverage of retatrutide, Lilly's triple-agonist obesity drug: trial results, side effects, the FDA timeline and what online products really are.
Retatrutide is an investigational weight-loss drug from Eli Lilly that acts on three hormone receptors at once: GIP, GLP-1 and glucagon. In Phase 3 trials it produced the largest average weight loss of any obesity drug so far, up to 28.3% of body weight over 80 weeks on the top dose. It is not FDA-approved. Lilly plans to submit it to FDA by the end of the first quarter of 2027.
retatrutide.review tracks the research, the regulatory timeline and the safety signals in plain English, with the source behind every number.
Where Retatrutide Stands (October 2026)
Retatrutide at a glance
Developer
Eli Lilly
How it works
Activates GIP, GLP-1 and glucagon receptors; once-weekly injection
FDA approval
Not approved; filing planned by Q1 2027
Positive Phase 3 trials
Five (TRIUMPH-1, -2, -3, -4 and TRANSCEND-T2D-1)
Top average weight loss
28.3% at 80 weeks on 12 mg (TRIUMPH-1)
Most common side effects
Nausea, diarrhea, constipation, vomiting; skin sensitivity (dysesthesia)
Legal access today
Clinical trials only
Start Here
- 1Retatrutide weight loss results: every trial, every dose, and what the 28% really means.
- 2Retatrutide side effects: what the Phase 3 trials reported, and the red flags.
- 3When will retatrutide be FDA approved?: the timeline and what's left.
- 4Retatrutide vs Ozempic, Wegovy and Zepbound: how it compares with semaglutide and tirzepatide.
- 5Tirzepatide and retatrutide for cutting: what the body-composition data says.
- 6What is retatrutide?: how the triple-hormone drug works, in plain English.
- 7Retatrutide vs tirzepatide: how it stacks up against Zepbound and Mounjaro.
- 8Retatrutide dosage in clinical trials: the doses tested and what each one did.
Why Retatrutide Gets So Much Attention
Semaglutide (Ozempic, Wegovy) works on one receptor, GLP-1. Tirzepatide (Mounjaro, Zepbound) adds GIP. Retatrutide adds a third, glucagon, which is thought to increase energy use and help clear fat from the liver. In its main obesity trial, nearly half of people on the 12 mg dose lost 30% or more of their body weight, numbers previously seen mainly after bariatric surgery.
The caveats matter just as much. Those are averages from trials with slow dose increases and medical supervision. There's no head-to-head result against tirzepatide yet, long-term data is limited, and about one in nine people on the top dose stopped because of side effects.
A Warning About Online Retatrutide
Retatrutide sold online as a "research peptide," "GLP-3" or "reta" is not the trial drug. It isn't approved for human use, FDA says it can't be compounded, and the dose, purity and sterility are unknown. We don't link to sellers or give dosing instructions. If you've taken an unverified product and feel unwell, see our overdose page.
How We Work
- 1Primary sources first: trial publications, ClinicalTrials.gov, FDA and Lilly's own disclosures.
- 2Every number with its dose, trial length, population and analysis method.
- 3Clear labels for news, analysis and personal stories.
- 4No miracle claims, no purchasing links, no dosing or injection instructions.
- 5Updates when new evidence changes the picture, with the date we checked.
FAQ
An investigational once-weekly injection from Eli Lilly that activates GIP, GLP-1 and glucagon receptors. It's being studied for obesity, type 2 diabetes, knee osteoarthritis and sleep apnea.
No. Lilly plans to submit it to FDA by the end of Q1 2027; a decision in late 2027 or 2028 is realistic.
In TRIUMPH-1, an average of 28.3% over 80 weeks on 12 mg (25.0% in the stricter published analysis).
Only by taking part in a clinical trial. Products sold online aren't approved or verified.
No. It provides general news and research context and doesn't replace advice from a qualified clinician.
