In May 2026, Eli Lilly released topline results from the pivotal Phase 3 TRIUMPH-1 trial. This large study evaluated Retatrutide in adults with obesity or overweight plus at least one weight-related condition (without type 2 diabetes).
Key Results at 80 Weeks (TRIUMPH-1)
- 12 mg dose: Average weight loss of 28.3% (approximately 70.3 lbs / 31.9 kg from baseline)
- 9 mg dose: Average weight loss of 25.9% (approximately 64.4 lbs)
- 4 mg dose: Average weight loss of 19.0% (approximately 47.2 lbs)
A significant number of participants on the higher doses achieved a BMI below 30 (no longer in the obesity range). Improvements were also observed in waist circumference, blood pressure, cholesterol markers, and inflammation indicators.
Important Context
These results come from a controlled clinical trial with specific inclusion criteria, gradual dose escalation, and close medical monitoring. Individual results in real-world settings (if the medication is approved in the future) may differ.
The trial used a stepwise titration schedule to help improve tolerability. Not all participants reached or stayed on the highest dose.
Ongoing Research
Additional Phase 3 trials in the TRIUMPH program are evaluating Retatrutide in people with type 2 diabetes, cardiovascular outcomes, sleep apnea, osteoarthritis, and other conditions. Results from these studies are expected to provide a fuller picture of the medication’s potential effects and safety.
Educational Summary
The weight loss percentages reported in TRIUMPH-1 represent some of the largest average reductions seen in pharmaceutical obesity trials to date. However, these are average results across study populations. Not everyone experiences the same degree of weight loss, and side effects must be considered.
Last reviewed: June 27, 2026
Important: This is educational information only. Retatrutide is investigational and not approved. This is not medical advice. Consult a qualified healthcare professional.