Retatrutide Shows Positive Inotropic Effects on Human Heart Tissue

Retatrutide is a novel triple agonist targeting GIP, GLP-1, and glucagon receptors, primarily recognized for its efficacy in treating obesity and type 2 diabetes. While its metabolic benefits are well-documented, the direct impact of retatrutide on the contractile function of human heart muscle, known as its inotropic effect, remains less explored. This study aimed to evaluate the direct inotropic effects of retatrutide on isolated human atrial preparations.

Retatrutide exhibited a significant and concentration-dependent positive inotropic effect, leading to an increase in myocardial contractile force. At a concentration of 100 nM, contractility was enhanced by 23.5% compared to control (p<0.01). This effect peaked at 300 nM, showing a robust 38.2% increase in force (p<0.001), before plateauing at higher concentrations. > The most significant finding was that retatrutide consistently and dose-dependently increased the force of contraction in human atrial tissue, with a maximal effect observed at 300 nM, leading to a 38.2% increase in contractility compared to control. Importantly, no negative inotropic effects were observed at any tested concentration, even at supraphysiological levels up to 1000 nM.