What it is
Retatrutide is a peptide made of 39 amino acids. It is made in a lab by the drug company Eli Lilly. It attaches to three receptors at once: GLP-1, GIP, and glucagon. GLP-1 and GIP are gut hormones that tell the pancreas to release insulin and lower hunger. Glucagon is a hormone that tells the liver to burn fat and release sugar. Glucagon alone would raise blood sugar. In trials, the GLP-1 and GIP effects outweighed it, so blood sugar went down. A fatty acid chain keeps it in the body for about 6 days. It is still being tested and is not approved anywhere. Other names: LY3437943, triple agonist.
What researchers study it for
- Body weight in people with obesity
- Blood sugar in type 2 diabetes
- Liver fat in fatty liver disease
- Heart rate and other safety measures
What the studies found
1. Adults with obesity lost up to 24.2 percent of body weight in 48 weeks.
A 2023 phase 2 trial gave 338 adults with obesity a weekly shot of retatrutide at one of several doses, or placebo. After 48 weeks, weight dropped 8.7 percent at the lowest dose and 24.2 percent at the highest. The placebo group lost 2.1 percent. Weight was still going down when the study ended. Stomach side effects were most common and rose with dose. Heart rate went up with dose, peaked at 24 weeks, then came down. Human data.
2. Blood sugar and weight dropped in type 2 diabetes.
A 2023 phase 2 trial gave retatrutide to 281 people with type 2 diabetes for 36 weeks. At the highest dose, HbA1c dropped 2.02 points and weight dropped 16.9 percent. Stomach side effects were common and rose with dose. No severe low blood sugar events were reported. Human data.
3. Liver fat dropped more than 80 percent.
A 2024 trial gave retatrutide to 98 people with fatty liver disease. Liver fat was measured with a special MRI scan. At the two highest doses, liver fat dropped 81.4 and 82.4 percent at 24 weeks. Most people at those doses reached a normal liver fat level. Human data.
4. The first human study set its timing in the blood.
This 2022 phase 1b study gave rising doses to people with type 2 diabetes. It stayed in the blood with a half-life of about 6 days. Blood levels rose evenly as the dose rose. Starting low and raising the dose slowly reduced stomach side effects. Human data.
How much research exists
Phase 1 and phase 2 human trials are published. Phase 3 trials, called TRIUMPH, are ongoing. No long-term safety or heart outcome data has been published yet.
Facts
- Formula: C221H342N46O68
- Weight: 4731.3 g/mol
- CAS number: 2381089-83-2
- Sequence: 39 amino acid chain with a fatty acid chain attached. Full sequence not listed here.
- Time in the blood: about 6 days
- Storage: keep in the fridge away from light.
Legal status
Not approved by the FDA or any other agency. It is an investigational drug in phase 3 trials.
For research use only. Not for human use. Nothing here is medical advice.