Retatrutide

What Is Retatrutide?

Retatrutide came out of Eli Lilly's incretin-biology research group — the same program responsible for tirzepatide. Where earlier compounds in this line activated one or two hormone receptors (GLP-1 alone, or GLP-1 and GIP together), Lilly's researchers designed Retatrutide as a single molecule capable of activating three receptors at once: GIP, GLP-1, and glucagon. Adding glucagon receptor activity on top of the two incretin pathways was a deliberate design choice, intended to add glucagon's own energy-expenditure and hepatic lipid-oxidation effects to the compound's profile.

Research Focus

Retatrutide's research profile is defined by its triple-receptor mechanism, and most published and ongoing research reflects that starting point directly. It sits in KYIN's Weight Loss / Metabolic category alongside MOTS-c and 5-Amino-1MQ, though its incretin-receptor mechanism is distinct from either compound's approach. See our Weight Loss / Metabolic research overview for how Retatrutide compares to Semaglutide, Tirzepatide, MOTS-c, and 5-Amino-1MQ.

• Triple-receptor (GIP/GLP-1/glucagon) agonism research
• Energy expenditure and metabolic rate studies
• Glycemic control research
• Body composition research models

Clinical & Preclinical Trial Data

The landmark preclinical paper, led by Coskun and colleagues, was published in Cell Metabolism in September 2022, and first-in-human research followed shortly after. A Phase 2 trial published in the New England Journal of Medicine in 2023 reported mean weight loss of up to 24.2% at 48 weeks in participants with obesity, and 16.9% at 36 weeks in a separate trial in participants with type 2 diabetes — the first published Phase 2 data for any triple GLP-1/GIP/glucagon agonist. The Phase 3 TRIUMPH-1 trial (2,339 adults with obesity or overweight and at least one weight-related condition, without type 2 diabetes) reported a mean weight loss of 28.3% at the 12mg dose over 80 weeks, with 45.3% of participants losing at least 30% of body weight — a threshold historically associated with bariatric surgery. A study extension in participants with baseline BMI ≥35 reached an average of 30.3% weight loss at 104 weeks, and all three doses tested (4mg, 9mg, 12mg) met their primary and key secondary endpoints against placebo. As of this writing, Retatrutide remains in Phase 3 clinical trials across several indications and has not received regulatory approval anywhere; it is not an approved drug.

Availability

Retatrutide is part of KYIN Peptides' standard catalogue — see the product page for pricing and available sizes, or contact us to order.