Peps
What phase 2 showed in 2023
Retatrutide activates three hormone receptors (GLP-1, GIP and glucagon). In the 2023 phase 2 obesity trial of 338 adults, average weight loss at 48 weeks reached 24.2% in the highest dose group versus 2.1% with placebo. A separate phase 2 trial in type 2 diabetes measured blood-sugar control rather than weight.
Phase 2 trials are designed to choose doses and look for safety signals. They are too small and short to settle how a drug performs across a broad population.
Source: Triple-Hormone-Receptor Agonist Retatrutide for Obesity - A Phase 2 Trial. ↗
TRIUMPH-1: obesity without diabetes
TRIUMPH-1 randomly assigned 2,339 adults with obesity but without diabetes to once-weekly retatrutide at one of three dose levels or to placebo for 80 weeks. Average weight change was about 18%, 24% and 25% lower across the retatrutide groups, compared with about 4% with placebo.
The trial also included 574 people with knee osteoarthritis, whose pain scores improved more than with placebo, and 243 people with obstructive sleep apnea, whose breathing interruptions per hour fell more than with placebo. Gastrointestinal effects were the most common adverse events.
Source: Retatrutide, a Triple Hormone Receptor Agonist, for Treatment of Obesity ↗
TRIUMPH-2: obesity with type 2 diabetes
TRIUMPH-2 enrolled 1,152 adults with overweight or obesity and type 2 diabetes at 92 centers in eight countries. After 80 weeks, average weight change was about 12%, 17% and 19% across the retatrutide groups versus about 5% with placebo, and 84% of participants completed the study drug.
People with type 2 diabetes usually lose less weight on these medicines than people without it, which this trial also showed. Gastrointestinal adverse events were again the most frequent.
What the new trials still cannot tell you
Both phase 3 trials were funded by Eli Lilly, which develops retatrutide. Eighty weeks of follow-up cannot show long-term safety, whether weight stays off after stopping, or effects on heart attacks and strokes, which need separate outcome trials.
Retatrutide was still investigational when this guide was checked, and the FDA has warned about unapproved GLP-1 products sold online. Trial results describe the manufacturer's study drug; they do not verify any product labeled as retatrutide elsewhere.
Source: Retatrutide, a Triple Hormone Receptor Agonist, for Treatment of Obesity ↗
Continue with the original research
Study examples are based on selected publication abstracts and the explicitly described source documents. This is not a systematic review or an individualized treatment guide. Editorial scope and methods.