Peptide Central
What retatrutide is, how it is classified, where its development stands, and what published research does and does not establish.
Retatrutide (development code LY3437943) is an investigational peptide that activates three receptors: the GIP, GLP-1 and glucagon receptors. Eli Lilly developed it. It is not a licensed medicine in the UK or, to our knowledge, anywhere else.
The rest of this page covers names, status and what the published evidence does and does not support.
"Retatrutide" is the name of the molecule. "Reta" is common shorthand for the same thing. Neither is the brand name of a licensed product, and no licensed product contains it.
Lyophilised powder in single-compound vials of 10mg, 20mg and 30mg, each certified as its own batch. The retatrutide buying guide lists the formats. The catalogue item is a laboratory reagent. No pen or ready-made injection is supplied, and listings that describe one are describing a different product.
Two peer-reviewed trials anchor the record, both sponsored by Eli Lilly:
Gastrointestinal events were the most commonly reported adverse events in both. TRIUMPH-2 also reported dysaesthesia and hypotension more often than placebo, and more discontinuations because of adverse events in some retatrutide groups.
These are findings about a clinical formulation given under a trial protocol to defined patient populations with medical supervision. They do not transfer to a research reagent, another supplier's material, or any use outside a trial. The retatrutide side effects page sets out the adverse events those trials reported.
This page cites no preclinical studies. The published record is mostly the sponsor's clinical reporting, and no in-vitro or animal finding is presented here as a human outcome.
| Compound | Receptors engaged | Status |
|---|---|---|
| Retatrutide | GIP, GLP-1, glucagon | Investigational |
| Tirzepatide | GIP, GLP-1 | Licensed medicine, including in the UK |
| Semaglutide | GLP-1 | Licensed medicine, including in the UK |
The three are separate molecules studied in separate trials, and results for one say nothing about another. The retatrutide, tirzepatide and semaglutide comparison sets out the receptor differences, and GLP-1 peptides versus classic research peptides explains why this class rests on a different evidence base.
Each vial is its own batch with its own certificate:
| Format | Batch | HPLC purity |
|---|---|---|
| 10mg | 100234 | 99.682% |
| 20mg | 100235 | 99.516% |
| 30mg | 100236 | 99.831% |
Product pages: 10mg, 20mg and 30mg. The reports are in the COA library. A certificate reports the identity and measured purity of the batch tested. It says nothing about biological effect and does not extend to other batches. The guides to reading a peptide COA and understanding HPLC purity explain the limits, and current prices are listed separately.
Materials sold on this site are supplied solely for non-clinical in-vitro laboratory research. They must not be ingested, injected, inhaled, applied or otherwise administered to a human or animal.
We do not provide dosing, routes of administration, treatment guidance, cosmetic-use guidance or in-vivo protocols. Preparation, storage and handling must follow a validated institutional SOP, the material documentation and an appropriate risk assessment.
Which adverse events were reported in published retatrutide trials, how often, and what those trials can and cannot tell you.
Research DocumentationWhat GHK-Cu is, how copper binds to the GHK tripeptide, how it is classified, and what published research does and does not establish.
Site materials are supplied solely for non-clinical in-vitro laboratory research. They must not be used in or on humans or animals. We do not provide dosing, routes of administration, treatment, cosmetic-use or in-vivo guidance. Read the legal and research-use terms.
