Who makes retatrutide? Eli Lilly and Company does. Here's how the Indianapolis drugmaker developed the drug, who owns it, and its current FDA status.
Retatrutide is made by Eli Lilly and Company, the Indianapolis-based pharmaceutical company that also developed tirzepatide, sold as Mounjaro and Zepbound. Lilly discovered retatrutide in its own laboratories under the code name LY3437943, and no other manufacturer is licensed to produce it. Retatrutide is still investigational and is not FDA-approved for any use in the United States.
Eli Lilly: The Company Behind Retatrutide
Eli Lilly and Company is a US drugmaker founded in 1876 and headquartered in Indianapolis, Indiana. It is one of the largest pharmaceutical companies in the world and markets medicines in roughly 100 countries.
When people ask what company makes retatrutide, Lilly is the only documented answer. The company's internal designation for the molecule, LY3437943, appears throughout clinical trial records, conference presentations, and patent filings tied to the drug.
What Is Retatrutide and How Does It Work?
Retatrutide is an investigational once-weekly injection that activates three hormone receptors at the same time: GIP, GLP-1, and glucagon. That triple mechanism is what separates it from older weight loss drugs, which usually target one or two receptors.
- GLP-1: may reduce appetite and slow how quickly the stomach empties.
- GIP: may influence how the body stores and breaks down fat.
- Glucagon: appears to increase energy expenditure.
In a Phase 2 trial published in the New England Journal of Medicine in 2023, adults with obesity who received 12 mg of retatrutide lost an average of about 24% of their body weight over 48 weeks. Those results are encouraging but preliminary, and Phase 3 data are still being collected.
Retatrutide Development Timeline and Trial Status
Lilly advanced retatrutide into a Phase 3 program called TRIUMPH, which spans obesity, type 2 diabetes, obstructive sleep apnea, knee osteoarthritis, and cardiovascular outcomes. The program began in 2023 and continues to enroll participants and report results.
As of early 2025, Eli Lilly has not submitted a new drug application for retatrutide to the FDA. Any launch date circulating online is a projection rather than a confirmed regulatory milestone.
Manufacturer questions come up across this whole drug class. If you have also wondered who makes semaglutide, the answer is Novo Nordisk, a different company entirely and Lilly's chief competitor in the weight loss market.
Who Owns Retatrutide? Patents, Rights, and Licensing
Retatrutide is owned by Eli Lilly and Company. Lilly holds the patents covering the molecule itself, its formulations, and its manufacturing processes, and it has not licensed the drug to any outside company.
That ownership is why searches for the retatrutide patent and questions about who invented retatrutide lead back to Lilly's own scientists and legal filings. Inventorship sits with Lilly researchers, and the company controls every stage of human testing.
How Retatrutide Compares to Other Weight Loss Drugs
The table below shows how the major incretin-based weight loss drugs differ by manufacturer, receptor target, and regulatory status.
| Drug | Manufacturer | Receptor targets | FDA status |
|---|---|---|---|
| Semaglutide (Ozempic, Wegovy) | Novo Nordisk | GLP-1 | Approved |
| Tirzepatide (Mounjaro, Zepbound) | Eli Lilly | GIP + GLP-1 | Approved |
| Retatrutide | Eli Lilly | GIP + GLP-1 + glucagon | Investigational, not approved |
| Liraglutide (Saxenda) | Novo Nordisk | GLP-1 | Approved |
Eli Lilly is the only company with an approved dual agonist and a triple agonist in late-stage development, which gives it a notable position in this market. That position does not make retatrutide available to patients today.
Can You Buy Retatrutide, and Who Is Actually Selling It?
Retatrutide cannot be legally sold as a prescription medicine in the United States because the FDA has not approved it. Vials labeled 'retatrutide' on research chemical websites are not made by Eli Lilly, and their purity, sterility, and actual contents are unverified.
Lilly does not distribute retatrutide to consumers, compounding pharmacies, or online sellers. Any vendor claiming to offer genuine Lilly retatrutide is describing a product that does not exist on the legal market.
Because no approved product exists, there is no official guidance on bac water for retatrutide. Searches such as how to mix retatrutide with bac water or how long does retatrutide last after adding bac water come from people handling grey-market vials on their own, a practice that carries risks including incorrect dosing, contamination, and infection.
Anyone considering an investigational weight loss drug should speak with a licensed healthcare professional instead of relying on unregulated sources. Approved options already exist, and a clinician can explain whether one of them fits your health situation.
Frequently Asked Questions
Who makes retatrutide?
Retatrutide is made by Eli Lilly and Company, the Indianapolis-based drugmaker that also developed tirzepatide. Lilly discovered the compound, holds the patents, and runs all of its clinical trials. No other company is licensed to manufacture retatrutide.
Is retatrutide FDA-approved?
No. Retatrutide is an investigational drug and has not been approved by the FDA for any indication. Eli Lilly is still running Phase 3 trials, so retatrutide cannot legally be prescribed or sold as a medicine in the United States.
Is retatrutide the same as tirzepatide?
No. Both drugs come from Eli Lilly, but tirzepatide targets two receptors (GIP and GLP-1) and is FDA-approved as Mounjaro and Zepbound, while retatrutide targets three receptors (GIP, GLP-1, and glucagon) and remains experimental.
This page provides educational research information and does not replace medical advice, diagnosis, or treatment.