Peptide data sheet
Retatrutide
GLP-1 · LY3437943
Verdict
promisingThe promising label reflects the strong early human trial data for weight and metabolic endpoints; it is tempered by the fact that retatrutide is still investigational, not FDA-approved, and the research-grade material sold for lab use is not the trial drug.
By MrPepTalks Editorial
Reviewed for scientific accuracy · research information, not medical advice
Last updated Reviewed
Quick answer
Retatrutide (LY3437943) is an experimental peptide that acts on three metabolic receptors at once. It is most commonly researched for weight management and blood-sugar outcomes, and unlike many research peptides it has real human trial data. It is still investigational and not FDA-approved; research-grade retatrutide is sold for laboratory research use only.
- Class
- Triple agonist (GIP / GLP-1 / glucagon receptor)
- Half-life
- roughly 6 days (reported), supporting once-weekly research schedules
- FDA status
- Not FDA-approved. Retatrutide is an investigational compound still in clinical trials; research-grade material sold for lab use is intended for laboratory research only.
- WADA banned?
- No
Which form actually works?
Injectable (subcutaneous)
Promising
The form used in the human trials and where essentially all of the research context lives. People report interest here because it matches how the compound was actually studied.
Oral
Unproven
Sometimes asked about by analogy to other metabolic drugs, but retatrutide's human data comes from the injectable form. An oral version is not where the studied evidence sits.
Third-Party Testing & Certificate of Analysis (COA)
A certificate of analysis (COA) is a lab document that reports what a specific batch of material actually contains. Reputable research suppliers publish one for every batch, tied to a lot number you can match against the vial you received.
- HPLC — purity
- High-performance liquid chromatography reports purity as a percentage: how much of the sample is the intended compound rather than impurities.
- Mass spectrometry (MS) — identity
- Mass spectrometry confirms identity by measuring the sample's molecular mass, so it matches the peptide the label names.
It also matters who ran the test. In-house results come from the seller's own lab; an independent third-party lab has no stake in the result, so its COA generally carries more weight. Look for a named testing laboratory, a batch or lot number, and a test date that lines up with the vial in hand.
New to reading one? This guide walks through a COA line by line: how to read a peptide COA.
Sources
- Jastreboff AM, Kaplan LM, Frias JP, et al. Triple-hormone-receptor agonist retatrutide for obesity: a phase 2 trial. N Engl J Med, 2023.
- Rosenstock J, Frias J, Jastreboff AM, et al. Retatrutide in people with type 2 diabetes: a phase 2 randomised controlled trial. Lancet, 2023.
- Coskun T, Urva S, Roell WC, et al. LY3437943 (retatrutide), a novel GIP/GLP-1/glucagon receptor triagonist: preclinical and early clinical characterization. Cell Metab, 2022.
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