Retatrutide

What is Retatrutide?

Retatrutide is an investigational once-weekly peptide drug from Eli Lilly that activates three metabolic hormone receptors at once: GLP-1R, GIPR, and glucagon receptor. In practice, that means appetite suppression, improved insulin signaling, and a glucagon-driven push toward hepatic fat oxidation and thermogenesis in the same molecule. This is why retatrutide sits beyond semaglutide and tirzepatide in pharmacological ambition.

From the BioHarmony report, reviewed 2026-09-08.

How it is thought to work

Simultaneous agonism of GLP-1, GIP, and glucagon receptors; the glucagon arm is intended to raise hepatic fat oxidation and energy expenditure while GLP-1/GIP constrain appetite and improve glycemia.

Safety watch-outs

• Persistent vomiting or dehydration
• Severe abdominal pain
• Blood in stool or black stool
• Symptoms of pancreatitis: severe upper abdominal pain radiating to back

Full risk profile in the BioHarmony report.

Dosing as published

No approved-label or study protocol is recorded for Retatrutide yet.

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