Retatrutide in type 2 diabetes mellitus and obesity: an overview.

This paper is a narrative review examining the clinical evidence on retatrutide (LY3437943), a novel triple receptor agonist targeting the glucagon receptor (GCGR), glucose-dependent insulinotropic polypeptide receptor (GIPR), and glucagon-like peptide-1 receptor (GLP-1R). The authors conducted an electronic literature search across Scopus, PubMed/MEDLINE, and Google Scholar to synthesize available findings. According to the review, studies in people with type 2 diabetes mellitus (T2DM) reported reductions in HbA1c of up to 2.16% and fasting glucose reductions of up to 69.1 mg/dL, alongside weight loss of up to 16.94%. In individuals with overweight or obesity (without T2DM), weight loss reached up to 26.56% (approximately 24.15 kg). Additional findings included reductions in BMI, waist circumference, and systolic blood pressure in those with T2DM and overweight/obesity, as well as a relative liver fat reduction of up to 86% in subjects with metabolic dysfunction-associated steatotic liver disease (MASLD). The most commonly reported adverse events were mild-to-moderate gastrointestinal symptoms, particularly at higher doses. The authors conclude that retatrutide's effects on glycemic control, weight, and potential pleiotropic benefits warrant further investigation through larger, longer-duration trials.

Why this grade: This is a narrative review synthesizing existing literature rather than a primary study, so its grade reflects the aggregated — but not independently generated — evidence base.