Some participants in the weight loss study of retatrutide, an investigational triple hormone receptor agonist, dropped out because they lost too much weight[query]. Retatrutide is a synthetic peptide that acts on GIP, GLP-1 and glucagon receptors, leading to significant weight loss[1][3][4]. In a study published in The New England Journal of Medicine, patients on the highest doses lost up to 26 kilograms after 48 weeks[1]. Phase 2 clinical trials showed an average weight loss of 24.2% after 48 weeks at 12 mg, comparable to bariatric surgery[3]. At 12 mg, participants lost 17.5% of their weight in 24 weeks, and about 30% of them lost 20% or more[2]. Another study in The Lancet reported a 2% drop in HbA1c and up to 17% weight reduction in patients with type 2 diabetes[1]. Retatrutide improves insulin sensitivity, reduces visceral fat and promotes metabolic improvements[2][3][4].