What Is Retatrutide (Reta)? Status, Trials and What It Is Not

As of September 29, 2026, retatrutide is not FDA-approved, and FDA states that it cannot be used in compounding under federal law. It is an investigational compound from Eli Lilly and Company that is still being studied in clinical trials. Majesta Health does not offer, prescribe or sell retatrutide.

Many people search for it under the short name "reta". This guide explains what the compound is, who makes it, what the published research says it acts on, where the clinical trials stand, and why a product sold online under that name is not the study drug. Every fact comes from a public record read on September 29, 2026: FDA's openFDA databases and web pages, the ClinicalTrials.gov registry, PubMed, and the manufacturer's own press releases. Quotes are word for word.

The page does not report amounts, schedules or trial result figures. No FDA-reviewed label exists to put them in context, and a status page is the wrong place for them.

*What this guide covers:*

• What retatrutide is, and what it is not
• Why it is called reta
• Who makes it, and what the manufacturer says about it
• What the published research says it acts on
• Where the clinical trials stand
• Why the reta sold online is not the study drug
• What is not known yet
• How to check its status yourself

Retatrutide at a glance

What is retatrutide?

Retatrutide is the name of an investigational compound that Eli Lilly and Company is studying under the research code LY3437943. Investigational means it is still being tested in clinical trials, and no FDA approval exists for it.

Lilly's press release of August 12, 2026 describes it this way: "Retatrutide is an investigational molecule in Phase 3 clinical trials for obesity, type 2 diabetes and other related indications."

Here is what retatrutide is not, as of September 29, 2026.

• It is not an FDA-approved medicine. The openFDA drug label database returns no label under the generic name retatrutide, and the Drugs@FDA database returns no application for it.
• It is not a compounded medication. FDA states: "Retatrutide and cagrilintide cannot be used in compounding under federal law."
• It is not a consumer product. Lilly's statement of August 12, 2026 reads: "No medicine containing retatrutide has yet been approved for human use by any regulatory agency in the world. It cannot be sold to consumers."
• It has no FDA-reviewed label, so there is no FDA-reviewed safety information for it.

Why is it called reta?

"Reta" is an informal short form made from the first four letters of retatrutide. It is not an official name. The primary sources on this page, including the ClinicalTrials.gov records, FDA's statements, the PubMed abstract and Lilly's press releases, use "retatrutide" or the code LY3437943, and none of them uses "reta".

The short name matters because it is the name many people type into a search engine, and search results for phrases such as "reta peptide" mix reference pages with storefront pages. A product page that says "reta" is making a claim about its contents that the buyer has no way to check. The section below on products sold online explains why.

As a word, then, reta and retatrutide name the same compound. As a product, anything labeled reta outside a registered study is a different question.

Who makes retatrutide, and what does the manufacturer say about it?

Eli Lilly and Company develops retatrutide. On ClinicalTrials.gov, Lilly is the lead sponsor on 32 of the 33 records that list retatrutide as an intervention, as read on September 29, 2026.

A press release is a company statement, not an independent finding. This page quotes Lilly only for the company's own position on the compound's legal status and its plans, and not for anything about how well the compound works.

Lilly's statements, word for word:

• July 23, 2026, in the section of a press release headed "About retatrutide": "Retatrutide is an investigational molecule that cannot be legally sold or marketed for human use."
• July 23, 2026, in the same release: "Lilly plans to submit a Biologics License Application (BLA) for retatrutide to FDA in Q1 2027"
• August 12, 2026: "No medicine containing retatrutide has yet been approved for human use by any regulatory agency in the world. It cannot be sold to consumers."

A plan to submit is not an application, and an application is not an approval. On September 29, 2026 the Drugs@FDA database returned no record for retatrutide, and none of the sources read for this page gives an FDA decision date. The approval question has its own page: is retatrutide FDA approved.

What does it act on, according to the published research?

The phase 2 obesity trial published in The New England Journal of Medicine in 2023 opens its abstract with this sentence: "Retatrutide (LY3437943) is an agonist of the glucose-dependent insulinotropic polypeptide, glucagon-like peptide 1, and glucagon receptors."

Lilly's own description, from its press release of July 23, 2026, puts the same idea in plainer words: "Retatrutide is a single molecule that activates the body's receptors for glucose-dependent insulinotropic polypeptide (GIP), glucagon-like peptide-1 (GLP-1), and glucagon."

In plain terms:

• A receptor is the site on a cell that a hormone acts through.
• An agonist is a substance that switches a receptor on.
• Retatrutide is described as acting on three receptors at once: GIP, GLP-1 and glucagon.

That is why it is often called a "triple agonist". The expanded access record on ClinicalTrials.gov uses the same idea, describing it as "an investigational GLP-1/GIP/glucagon triple receptor agonist being studied for chronic weight management".

A description of which receptors a compound acts on is not evidence about whether it works or whether it is appropriate for any person. Those questions are what the trials and, if one is ever filed and approved, an FDA review exist to answer. For background on the GLP-1 part of the name, see what a GLP-1 medication is.

Where do the clinical trials stand?

On September 29, 2026, the ClinicalTrials.gov registry returned 33 records that list retatrutide as an intervention: 14 phase 1 records, 4 phase 2 records, 14 phase 3 records and 1 expanded access record. Across all 33, the registry shows 21 Completed, 9 Active, not recruiting, 2 Recruiting and 1 Available.

The 14 phase 3 records look like this. The descriptions summarize each record's conditions and title in plain words.

Source: ClinicalTrials.gov API v2, query by intervention "retatrutide", fields NCTId, BriefTitle, OverallStatus, Phase and HasResults; read September 29, 2026.

Three points about reading this table:

1. A registry status describes where a study is in its life. Completed does not mean the results are public, and it does not mean the compound is approved.
2. Results posted in the registry and results published in a journal are two different things. PubMed lists a report of one phase 3 study in type 2 diabetes, TRANSCEND-T2D-1 (NCT06354660), in The Lancet on June 13, 2026, while the registry record for that study still showed no posted results on September 29, 2026. In the registry, only two phase 2 records, NCT04881760 and NCT04867785, have posted results.
3. Lilly has described other phase 3 studies in press releases. Those are company announcements, not registry results and not peer-reviewed reports, and this page does not repeat their figures.

The expanded access record, NCT07629401, is titled "Pre-approval Expanded Access of Retatrutide (LY3437943)" and showed the status Available on September 29, 2026, with Eli Lilly and Company as sponsor. Its summary describes "pre-approval single-patient expanded access" for a narrowly defined group of adults with severe obesity and serious obesity-related complications who cannot join an ongoing trial. Expanded access is not an approval.

Is the reta sold online the same thing as the study drug?

No buyer can confirm that it is. The study drug is the compound tested under registered study protocols, with a named sponsor and a registry record behind it. A product sold online under the name reta has none of that record behind it, and the manufacturer says that no medicine containing retatrutide can be sold to consumers.

FDA has addressed these products directly. Its page on unapproved GLP-1 drugs, content current as of 09/01/2026, says: "FDA has warned companies that have illegally sold unapproved drugs containing semaglutide, tirzepatide, retatrutide, survodutide or mazdutide that are falsely labeled 'for research purposes' or 'not for human consumption.'" The same page adds: "The agency urges consumers not to purchase these products which are of unknown quality and may be harmful to their health."

The same FDA page lists among the companies it has warned: "Telehealth companies for marketing unapproved drugs such as retatrutide, including instances of direct marketing to consumers."

Lilly's chief medical officer, David A. Hyman, M.D., was quoted in the release of August 12, 2026: "What is being sold on the black market is not a medicine".

Three plain points follow.

• A label that says "for research purposes" or "not for human consumption" does not make a sale to people lawful. FDA calls that labeling false when the product is sold for human use.
• A vial or pen labeled reta comes with no FDA-reviewed label, and its contents cannot be verified by the buyer.
• A code or a listing in an FDA database is not an approval. On September 29, 2026 a free-text search of the openFDA label database returned 12 listing documents that mention retatrutide, none of them carrying openFDA drug fields, and a search of the openFDA NDC data returned 12 records, all listed as bulk ingredients. FDA's National Drug Code Directory page says: "Inclusion in the NDC Directory does not indicate that FDA has verified the information provided or that the products are FDA-approved."

If you have used a product sold as reta and you feel unwell, talk to a physician and tell them exactly what the product was and where it came from. FDA's page encourages health care professionals, patients and compounders to report adverse events or quality problems to its MedWatch Adverse Event Reporting program.

What is not known about retatrutide yet?

A great deal, and the gaps are part of its status.

• No FDA-reviewed safety information. There is no FDA-reviewed label, so there is no FDA-reviewed list of side effects, warnings, contraindications or drug interactions.
• No FDA decision. Whether FDA will approve an application, for which uses and when is not known. Lilly has said it plans to submit an application in Q1 2027; that is a plan, not a filing.
• No phase 3 results in the registry. None of the 14 phase 3 records had posted results on September 29, 2026, and the cardiovascular and kidney outcomes study, NCT06383390, was still Active, not recruiting.
• No approved labeling on who should not use it. An approved label would name contraindications and warnings. None exists.
• Nothing reliable about products sold outside trials. What is inside a product labeled reta and sold online cannot be verified by the buyer.

For what the published trial record says about side effects, and what it leaves out, see retatrutide side effects.

Where can you check its status yourself?

All of these records are public and free, and none of them needs an account.

1. Check for an FDA-approved label. Open this openFDA address in a browser: https://api.fda.gov/drug/label.json?search=openfda.generic_name:%22retatrutide%22&limit=1. On September 29, 2026 it answered "No matches found!".
2. Check for an FDA application. Open this Drugs@FDA address through openFDA: https://api.fda.gov/drug/drugsfda.json?search=products.active_ingredients.name:%22RETATRUTIDE%22&limit=1. On September 29, 2026 it also answered "No matches found!".
3. Check the trials. Search ClinicalTrials.gov for retatrutide as the intervention, and read the status and the results tab of each record.
4. Check FDA's own statement. Open FDA's page "FDA's Concerns with Unapproved GLP-1 Drugs Used for Weight Loss" and note the "Content current as of" date at the bottom.
5. Read listings with care. A document or code in an FDA database is not an approval. FDA's NDC Directory page says: "Assignment of an NDC number does not in any way denote FDA approval of the product."

This page is re-checked at least every 90 days and at any FDA action on retatrutide. If the records above change, the records are right and this page is out of date. For how compounding law is organized, see 503A pharmacies vs 503B outsourcing facilities. For how an approved medicine's label is laid out, see how to read a prescription label.

What the primary sources say

• U.S. Food and Drug Administration, openFDA drug label API, query by generic name (accessed September 29, 2026): the query https://api.fda.gov/drug/label.json?search=openfda.generic_name:%22retatrutide%22&limit=1 returned "No matches found!"
• U.S. Food and Drug Administration, Drugs@FDA through openFDA, query by active ingredient (accessed September 29, 2026): the query https://api.fda.gov/drug/drugsfda.json?search=products.active_ingredients.name:%22RETATRUTIDE%22&limit=1 returned "No matches found!"
• U.S. Food and Drug Administration, FDA's Concerns with Unapproved GLP-1 Drugs Used for Weight Loss, content current as of 09/01/2026 (accessed September 29, 2026): "Retatrutide and cagrilintide cannot be used in compounding under federal law."; "FDA has warned companies that have illegally sold unapproved drugs containing semaglutide, tirzepatide, retatrutide, survodutide or mazdutide that are falsely labeled 'for research purposes' or 'not for human consumption.'"; "Telehealth companies for marketing unapproved drugs such as retatrutide, including instances of direct marketing to consumers."
• U.S. Food and Drug Administration, National Drug Code Directory, content current as of 03/04/2026 (accessed September 29, 2026): "Inclusion in the NDC Directory does not indicate that FDA has verified the information provided or that the products are FDA-approved."; "Assignment of an NDC number does not in any way denote FDA approval of the product."
• ClinicalTrials.gov, U.S. National Library of Medicine, API v2 query by intervention retatrutide (accessed September 29, 2026): totalCount 33; 14 records with phase "PHASE3", of which 5 "COMPLETED", 8 "ACTIVE_NOT_RECRUITING" and 1 "RECRUITING"; "hasResults" false on all 14
• ClinicalTrials.gov, record NCT07629401 (accessed September 29, 2026): "Pre-approval Expanded Access of Retatrutide (LY3437943)"; overall status "AVAILABLE"; lead sponsor "Eli Lilly and Company"
• PubMed, Jastreboff AM et al., Triple-Hormone-Receptor Agonist Retatrutide for Obesity, A Phase 2 Trial, N Engl J Med 2023 (PMID 37366315) (accessed September 29, 2026): "Retatrutide (LY3437943) is an agonist of the glucose-dependent insulinotropic polypeptide, glucagon-like peptide 1, and glucagon receptors."
• PubMed, TRANSCEND-T2D-1 phase 3 trial report, Lancet 2026 (PMID 42250575) (accessed September 29, 2026): publication type "Clinical Trial, Phase III"; publication date "2026 Jun 13"
• Eli Lilly and Company via PR Newswire, press release of July 23, 2026 (accessed September 29, 2026): "Retatrutide is an investigational molecule that cannot be legally sold or marketed for human use."; "Retatrutide is a single molecule that activates the body's receptors for glucose-dependent insulinotropic polypeptide (GIP), glucagon-like peptide-1 (GLP-1), and glucagon."; "Lilly plans to submit a Biologics License Application (BLA) for retatrutide to FDA in Q1 2027"
• Eli Lilly and Company via PR Newswire, press release of August 12, 2026 (accessed September 29, 2026): "Retatrutide is an investigational molecule in Phase 3 clinical trials for obesity, type 2 diabetes and other related indications."; "No medicine containing retatrutide has yet been approved for human use by any regulatory agency in the world. It cannot be sold to consumers."; "What is being sold on the black market is not a medicine"

Every source is listed with its address below.

This article is for informational purposes only and does not constitute medical advice. Retatrutide is an investigational compound that is not FDA-approved as of September 29, 2026. Nothing here describes how to obtain it or recommends its use outside a registered clinical trial. Record entries and statements are quoted word for word from the public sources named above as read on September 29, 2026; those records change, so check them yourself before relying on this page.