Metabolic Research
Retatrutide (LY3437943) is a triple receptor agonist developed by Eli Lilly targeting GLP-1, GIP, and glucagon receptors simultaneously. It represents the next generation of the incretin-based research compound class, extending the dual agonism of Tirzepatide with the addition of glucagon receptor (GCGR) activation — a mechanism studied for its potential contribution to hepatic lipolysis and thermogenesis pathways.
In May 2026, Eli Lilly reported topline results from TRIUMPH-1, the first Phase 3 obesity trial for Retatrutide. The trial examined once-weekly subcutaneous administration across a 72-week period. Early topline data showed significant reductions in body weight, extending the efficacy signal seen in Phase 2 trials where participants on the highest dose achieved approximately 24% mean body weight reduction at 48 weeks — the largest weight loss signal recorded in a clinical trial for any compound in the GLP-1 class at that time.
The key mechanistic question researchers have focused on is what the glucagon receptor component adds beyond the dual GIP/GLP-1 agonism of Tirzepatide. Preclinical data suggests the glucagon receptor activation drives hepatic lipolysis — the breakdown of fat stored in the liver — and increases thermogenesis (heat production as a byproduct of metabolism). These effects appear additive to the insulin sensitization and satiety effects of GLP-1/GIP co-activation.
For researchers studying multi-receptor metabolic pathways, Retatrutide's triple agonist profile makes it uniquely valuable for comparative protocol design. Studies seeking to isolate the glucagon receptor contribution to metabolic outcomes can use Retatrutide and Tirzepatide in parallel arms — the difference between the two compounds in terms of receptor targets is specifically the glucagon receptor component.
Plato Peptides supplies Retatrutide in 10mg and 20mg vials at ≥98% HPLC purity with independent third-party COA documentation. All compounds are sold strictly for research and laboratory use only.