Retatrutide – FAQ

Retatrutide is a triple-agonist compound from Eli Lilly and the first to act simultaneously on the GLP-1, GIP and glucagon receptors. It is currently in Phase III trials (TRIUMPH program) for obesity and type-2 diabetes, and available through approved clinical study programs for eligible participants.

Regular FDA and EMA approval is expected at the earliest by late 2026 or 2027, depending on completion of the TRIUMPH-1 and TRIUMPH-2 trials. Until then, Retatrutide is only available inside clinical studies, including our partner clinic's approved program.

In Phase II data at the highest dose (12 mg weekly) an average weight loss of about 24% of body weight was achieved after 48 weeks — substantially more than Semaglutide (~15%) and Tirzepatide (~20–22%).

Semaglutide (Ozempic, Wegovy) is a mono-agonist at the GLP-1 receptor. Tirzepatide (Mounjaro, Zepbound) is a dual-agonist at GLP-1 and GIP. Retatrutide additionally targets the glucagon receptor, thereby increasing basal metabolic rate — a mechanism the other two lack.

The most common side effects are gastrointestinal: nausea, vomiting, diarrhea and constipation, mostly at treatment start and dose-dependent. Trials also observed mild heart-rate increases. Long-term safety data are still pending.

Retatrutide is not available as a finished pharmaceutical over the counter. Safe access is possible through approved clinical study programs, such as our partner clinic's. 'Research peptides' offered online are unregulated and not part of an approved study program — purity, dosage and sterility are unknown and use carries substantial health risks.

TRIUMPH-1 is the pivotal Phase III registration trial of Retatrutide in adults with obesity. It evaluates safety and efficacy over 80 weeks versus placebo. Results are expected in 2026 as the basis for the regulatory submission.

The GLP-1 receptor drives brain satiety and slows gastric emptying. The GIP receptor improves insulin sensitivity and lipid handling. The glucagon receptor directly raises resting energy expenditure. The three pathways act synergistically.