Triple hormone receptor agonist (GIP/GLP-1/glucagon) · Also known as LY3437943
A next-generation triple agonist peptide that simultaneously activates GIP, GLP-1, and glucagon receptors. In Phase 3 trials, participants lost an average of 28.7% of their body weight at the highest dose, making it one of the most potent weight loss agents ever studied.
Developed by Eli Lilly, retatrutide is a 39-amino-acid peptide linked to a fatty acid chain that extends its half-life to roughly six days, enabling once-weekly dosing. Unlike dual agonists such as tirzepatide, retatrutide adds glucagon receptor activation, which increases energy expenditure and promotes fat burning on top of the appetite-suppressing effects of GLP-1 and GIP. Phase 3 results from the TRIUMPH program demonstrated average weight loss of 71.2 lbs (32.3 kg) at 68 weeks on the 12 mg dose. Retatrutide is not yet FDA-approved and is currently in late-stage clinical trials.
Retatrutide activates three receptors at once. Its GLP-1 receptor activity suppresses appetite and slows gastric emptying, making you feel full longer. GIP receptor activation enhances insulin secretion in a glucose-dependent manner and plays a role in lipid metabolism, helping reduce fat storage.
The third component - glucagon receptor activation - is what sets retatrutide apart from dual agonists. Glucagon promotes hepatic glucose production, thermogenesis, and lipid mobilization, meaning your body actively burns more energy and breaks down stored fat. This three-pronged approach creates synergistic metabolic benefits that exceed what any single or dual agonist can achieve alone.
2 mg/week
Weeks 1-49-12 mg/week
After titration periodMost side effects tend to improve as your body adjusts.