Retatrutide

Retatrutide, developed as LY3437943, is one molecule that agonises three receptors: GLP-1R, GIPR and the glucagon receptor GCGR. Most incretin research compounds hit one or two.

The potency across those three is deliberately uneven, and the numbers are the most useful thing to know before designing around it. Reported EC50 values are 0.0643 nM at GIPR, 0.775 nM at GLP-1R and 5.79 nM at GCGR. Measured against the endogenous hormones at each receptor, retatrutide is about 8.9 times more potent at GIPR, and roughly 0.3 and 0.4 times as potent at GCGR and GLP-1R. It is a GIPR-dominant molecule with glucagon activity added, not an equal three-way agonist.

Cryo-electron microscopy structures have been published for retatrutide bound to each of the three receptors, so the binding poses are available in the structural literature rather than inferred.

Phase 2 clinical trials have measured body weight and glycaemic endpoints. Those are findings from that research, described here as such. We make no claim about what this compound does in any individual.

Compared with tirzepatide, the difference is the third receptor. Researchers comparing the two are usually isolating what glucagon-receptor agonism adds to a GIP and GLP-1 background.

Supplied as a lyophilised powder at ≥99% purity by HPLC, with batch LC-MS identity confirmation and a certificate of analysis. Reconstitute with bacteriostatic water. Store the sealed vial at -20°C and keep reconstituted solution at 2-8°C, protected from light.

For in-vitro laboratory research only. Not for human or veterinary use.