Retatrutide Research

Jastreboff AM, Kaplan LM, Frías JP, et al. — Retatrutide Phase 2 Obesity Trial Investigators

The landmark Phase 2 trial of retatrutide in 338 adults with obesity. At the highest dose (12mg), participants lost an average of 24.2% of their body weight over 48 weeks — with weight loss curves that had not yet plateaued at trial end, suggesting even greater losses with longer treatment. Every single participant in the 12mg group achieved at least 5% weight loss, and 62% achieved 20% or more. These are the highest weight loss numbers ever recorded in a pharmacological trial and exceed those of bariatric surgery in some comparisons.

Rosenstock J, Frias JP, Jastreboff AM, et al.

Companion Phase 2 trial of retatrutide in 281 adults with type 2 diabetes. Retatrutide produced significant reductions in HbA1c (up to 2.02 percentage points) and body weight (up to 16.94%) compared to placebo over 36 weeks. The triple agonist mechanism improved glycemic control more than existing single and dual agonists, while also producing substantial weight loss — establishing the metabolic breadth of the compound beyond obesity alone.

ClinicalTrials.gov

Retatrutide entered Phase 3 clinical trials under the TRIUMPH program in 2024, with seven trials evaluating it across obesity, type 2 diabetes, cardiovascular outcomes, and related metabolic conditions. As of early 2026 Phase 3 results are beginning to emerge. If the Phase 3 data replicates the Phase 2 findings, retatrutide would represent the most effective pharmacological weight loss treatment ever approved. This page will be updated as Phase 3 results are published.