Retatrutide (LY3437943)
Triple GLP-1/GIP/Glucagon Agonist · Weight Loss & Diabetes
Overview
Novel triple hormone receptor agonist targeting GLP-1, GIP, and glucagon receptors. Phase II trials demonstrated 24.2% weight loss at 48 weeks—the highest recorded for obesity medications.
Activates GLP-1 for appetite suppression, GIP for insulin sensitivity, and glucagon for increased energy expenditure and hepatic fat oxidation.
Clinical trials show 17.5% weight loss at 24 weeks and 24.2% at 48 weeks.
Continuous weight loss with no plateau at 48 weeks suggests greater long-term potential.
Addresses obesity through appetite suppression, energy expenditure, and metabolic efficiency.
Mechanism
Novel triple hormone receptor agonist targeting GLP-1, GIP, and glucagon receptors. Phase II trials demonstrated 24.2% weight loss at 48 weeks—the highest recorded for obesity medications.
Activates GLP-1 for appetite suppression, GIP for insulin sensitivity, and glucagon for increased energy expenditure and hepatic fat oxidation.
Clinical trials show 17.5% weight loss at 24 weeks and 24.2% at 48 weeks.
Research areas
- Novel triple hormone receptor agonist targeting GLP-1, GIP, and glucagon receptors. Phase II trials demonstrated 24.2% weight loss at 48 weeks—the highest recorded for obesity medications.
- Activates GLP-1 for appetite suppression, GIP for insulin sensitivity, and glucagon for increased energy expenditure and hepatic fat oxidation.
- Clinical trials show 17.5% weight loss at 24 weeks and 24.2% at 48 weeks.
- Continuous weight loss with no plateau at 48 weeks suggests greater long-term potential.
- Addresses obesity through appetite suppression, energy expenditure, and metabolic efficiency.
Research notes
- Gastrointestinal effects (nausea, vomiting, diarrhea)—typically mild to moderate
- Heart rate increases—common especially in first 24 weeks
- Severe persistent nausea or vomiting preventing adequate nutrition
- Signs of pancreatitis: severe abdominal pain radiating to back
- Severe hypoglycemia symptoms: confusion, dizziness, sweating
References
- pubmed.ncbi.nlm.nih.gov/37366315/
- pubmed.ncbi.nlm.nih.gov/40609566/
- pubmed.ncbi.nlm.nih.gov/41090431/
- pubmed.ncbi.nlm.nih.gov/39019866/
- pubmed.ncbi.nlm.nih.gov/37385280/
- pubmed.ncbi.nlm.nih.gov/38858523/
Questions
What makes retatrutide's 24.2% weight loss so much higher than semaglutide's 15-20%?
Retatrutide is a triple agonist activating GLP-1, GIP, and glucagon receptors simultaneously. GLP-1 suppresses appetite, GIP improves insulin sensitivity, and glucagon increases energy expenditure and fat oxidation. Semaglutide only activates GLP-1. The triple mechanism addresses obesity through three distinct…
Does retatrutide actually reduce liver fat, or just overall fat loss?
It specifically targets liver fat. Clinical trials showed up to 82% liver fat reduction and complete normalization in 90% of participants at 24 weeks. This isn't just general weight loss—it's preferential hepatic fat oxidation, making retatrutide potentially valuable for NAFLD/MASH, not just obesity.
Could I eventually stop taking retatrutide, or do I need it forever?
Unknown. Phase 2 trials ran 48 weeks—long enough to achieve 24% weight loss but not long enough to study discontinuation. Clinical with semaglutide suggests weight returns if stopped. Phase 3 TRIUMPH trials (results expected 2026) should provide data on maintenance therapy vs. indefinite use.