Retatrutide's first phase 3 trial: better glucose and up to 15.3% less weight

TRANSCEND-T2D-1, published in June 2026 in The Lancet, with 537 people with type 2 diabetes.

TRANSCEND-T2D-1 is the first published phase 3 trial of retatrutide. For 40 weeks, 537 adults with type 2 diabetes not controlled by diet and exercise alone received 4, 9 or 12 mg weekly or placebo, at 48 sites in the USA, Mexico and India.

HbA1c fell by 1.69 to 1.94 points depending on dose, versus 0.81 with placebo. Weight fell by 11.5 to 15.3%, versus 2.6% with placebo. The most frequent adverse events were mild-to-moderate gastrointestinal events that eased over time.

In three points

First published phase 3 result for retatrutide
HbA1c −1.94 and weight −15.3% at the highest dose
Sites in Mexico, the USA and India took part

Compounds mentioned

Retatrutide

Original source: Efficacy and safety of retatrutide, a GIP, GLP-1, and glucagon receptor agonist, in people with type 2 diabetes and inadequate glycaemic control with diet and exercise (TRANSCEND-T2D-1): a double-blind, randomised, phase 3 trial
PubMed · The Lancet

Plain-language summary by SYNTRA LABS based on the original publication and checked against its source. It is not medical advice or a recommendation for use. SYNTRA LABS compounds are for research use only and not for human consumption.