Retatrutide is generating major buzz as possibly the most powerful weight loss drug ever developed. Here is a clear explanation of what it is, how it works, and what we know so far.
What Is Retatrutide?
Retatrutide is an experimental weight loss drug developed by Eli Lilly. It is a "triple agonist" — meaning it activates three hormone receptors simultaneously: GLP-1, GIP, and glucagon. Most existing weight loss drugs like Ozempic and Mounjaro only target one or two of these receptors.
How Does It Work?
By targeting all three receptors, retatrutide affects appetite, blood sugar regulation, and energy burning at the same time. Clinical trials have shown it can produce weight loss of up to 24% of body weight — significantly more than current approved drugs.
How Does It Compare to Ozempic and Mounjaro?
- Ozempic (semaglutide): ~15% average weight loss
- Mounjaro (tirzepatide): ~21% average weight loss
- Retatrutide: up to 24% average weight loss in trials
Is Retatrutide FDA Approved?
As of June 2026, retatrutide is still in clinical trials and has not received FDA approval. It is not yet available by prescription. Eli Lilly has submitted data to the FDA and a decision is expected in late 2026 or 2027.
Who Might Be Eligible When Approved?
Like other GLP-1 drugs, retatrutide is expected to be prescribed for adults with obesity (BMI 30+) or overweight adults (BMI 27+) with at least one weight-related condition such as type 2 diabetes or high blood pressure.
What Are the Side Effects?
Trial participants reported nausea, vomiting, diarrhea, and decreased appetite — similar to existing GLP-1 drugs. These typically improve after the first few weeks of treatment.