About Retatrutide

Retatrutide (LY3437943) is an investigational triple-hormone receptor agonist being developed by Eli Lilly for obesity and type 2 diabetes. Unlike single or dual agonists, retatrutide targets three receptors simultaneously: GIP, GLP-1, and glucagon. This triple-action mechanism works by reducing appetite, slowing gastric emptying, improving insulin secretion, and increasing energy expenditure. Retatrutide is administered as a once-weekly injection. Phase 2 clinical trials showed participants lost up to 24.2% of body weight over 48 weeks. Retatrutide is currently in Phase 3 clinical trials and is not yet FDA-approved. There are no generic alternatives for retatrutide.

Common questions about Retatrutide

Is retatrutide FDA-approved?

No, retatrutide is not FDA-approved. It is currently in Phase 3 clinical trials (TRIUMPH trials) conducted by Eli Lilly. Based on current timelines, FDA approval could potentially occur in 2026 or 2027, with commercial availability following shortly after. Any products claiming to be retatrutide sold online are unapproved and potentially dangerous.

How is retatrutide different from Ozempic or Mounjaro?

Retatrutide is a "triple agonist" that activates three hormone receptors: GIP, GLP-1, and glucagon. Ozempic (semaglutide) activates only the GLP-1 receptor, while Mounjaro (tirzepatide) activates two receptors (GIP and GLP-1). The addition of glucagon receptor activation may increase energy expenditure and fat burning, potentially leading to greater weight loss.

How much weight can you lose on retatrutide?

In Phase 2 clinical trials, participants taking the highest dose (12mg) lost an average of 24.2% of their body weight over 48 weeks. The Phase 3 TRIUMPH-4 trial reported up to 28.7% weight loss at 68 weeks. These results exceed those seen with currently approved GLP-1 medications.

What are the common side effects of retatrutide?

The most frequently reported side effects in clinical trials were gastrointestinal, including nausea, diarrhea, vomiting, and constipation. These side effects were dose-dependent, occurring more frequently at higher doses, and were primarily mild to moderate in severity. Most side effects occurred during the dose escalation period and improved over time.

Can I buy retatrutide online or from a compounding pharmacy?

No. The FDA has warned against purchasing retatrutide from any source, as it is not approved for any use. Compounded versions are illegal and potentially dangerous. The only legitimate way to access retatrutide is through participation in an official Eli Lilly clinical trial.

When will retatrutide be available?

Based on current Phase 3 trial timelines, Eli Lilly could submit for FDA approval in late 2025 or early 2026. If approved, commercial availability is expected in late 2026 or early 2027. However, delays are possible depending on trial results and FDA review.

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