Retatrutide research guide
What Is Retatrutide?
Retatrutide is an investigational medicine developed by Eli Lilly and studied in clinical trials. This guide explains how it works, what recent research has reported, and how it differs from semaglutide and tirzepatide.
How does retatrutide work?
Lilly describes retatrutide as a single molecule that activates three hormone receptors: GIP, GLP-1 and glucagon. For this reason, it is described as a triple agonist. “GLP-3” is an informal term, not a scientifically accurate classification.
GIP receptor
One of the three receptor pathways being studied.
GLP-1 receptor
A receptor pathway also targeted by medicines such as semaglutide.
Glucagon receptor
The third receptor pathway in retatrutide’s investigational profile.
How is it different from semaglutide and tirzepatide?
These medicines have different active ingredients and receptor profiles. Retatrutide is still investigational; semaglutide and tirzepatide are established medicines with approved uses that vary by product and country. They should not be treated as interchangeable.
Retatrutide
GIP, GLP-1 and glucagon receptor activity; under clinical study.
Tirzepatide
GIP and GLP-1 receptor activity.
Semaglutide
GLP-1 receptor activity.
What have clinical trials reported?
In the Phase 3 TRIUMPH-2 trial, Lilly studied adults with type 2 diabetes and obesity or overweight. In the 12 mg group, the reported average weight reduction was 20.8% after 80 weeks.
This is an average from a specific clinical trial group and study period. It does not predict an individual’s result or establish retatrutide as an approved treatment. Lilly also reported gastrointestinal side effects in the trial, including nausea, diarrhea, constipation and vomiting.
How should product claims be evaluated?
A product name or label alone cannot verify which substance a vial contains. Laboratory testing can assess different things depending on the methods ordered, such as identity, amount or impurities in the sample. Ask what each test covers and which sample it applies to.
Calling a product a “peptide” does not by itself verify its contents, quality or regulatory status.
What is retatrutide’s current status?
Lilly’s FAQ, updated in September 2026, says retatrutide has not been approved by any regulatory agency and is not available for public use. Lilly says it is being studied in Phase 3 clinical trials.
For Thailand-specific medicine registration information, use the Thai FDA medicine product search .
Frequently asked questions
Is retatrutide a GLP-1 medicine?
Retatrutide activates the GLP-1 receptor, but it is being studied as a triple agonist involving GIP, GLP-1 and glucagon receptors.
Is retatrutide the same as Mounjaro or Ozempic?
No. Mounjaro contains tirzepatide and Ozempic contains semaglutide. Retatrutide is a different investigational molecule.
Is retatrutide approved for public use?
Lilly’s latest published information says it has not been approved by any regulatory agency and is not available for public use.
Can a laboratory test prove that a product is retatrutide?
A suitable identity test can help identify the substance in the sample tested. The result depends on the lab method and the scope of the report; it does not establish approval or prove that other samples are identical.
Sources and further reading
- Eli Lilly: What to know about retatrutide
- Eli Lilly: Phase 3 TRIUMPH-2 results
- Thai FDA: Medicine product search