Retatrutide: The Triple Agonist That Outperforms Ozempic and Mounjaro
Eli Lilly is developing a new peptide that could redefine obesity treatment: retatrutide (LY3437943).
AN UNPRECEDENTED TRIPLE AGONIST
Unlike semaglutide (GLP-1 alone) and tirzepatide (GLP-1 + GIP), retatrutide targets THREE receptors:
- GLP-1 (like Ozempic)
- GIP (like Mounjaro)
- Glucagon
This triple action gives it superior efficacy in clinical trials.
PHASE 2 RESULTS (NEJM)
Published in the New England Journal of Medicine:
- Average weight loss at 48 weeks: -24.2% (58 lbs / 26 kg)
- Placebo group: -2.1%
- Some participants: up to -31% in 8 months
For comparison, tirzepatide (Mounjaro) achieves -22.5% in phase 3 studies.
ACCELERATED TIMELINE
In February 2025, Eli Lilly announced that phase 3 data would be released earlier than expected:
- Originally expected: February 2026
- New projection: during 2025
The 68-week study involves obese patients with knee osteoarthritis.
SIDE EFFECTS TO WATCH
Reported adverse effects include:
- Nausea (common during titration)
- Gastrointestinal disorders
- Kidney stone cases reported
FDA approval is expected in several years, pending completion of phase 3 trials.
This peptide illustrates ongoing innovation in the field of incretin agonists.
