GLP 3 (Reta)
A synthetic triple GIP, GLP-1, and glucagon receptor agonist (39-amino-acid incretin analog), supplied as sterile lyophilized powder for in-vitro metabolic research.
What is GLP-3 (Reta)?
GLP-3 (Reta) (development code LY3437943) is a synthetic single-molecule "triple agonist" that activates three metabolic hormone receptors at once — the GIP receptor, the GLP-1 receptor, and the glucagon receptor. Engaging all three pathways simultaneously drives glucose-dependent insulin secretion through the two incretin arms while adding glucagon-receptor agonism implicated in energy expenditure, the pharmacological rationale that distinguishes it from single (GLP-1 (Sema)) and dual (GLP-2 (Triz)) incretin agonists.
Research areas where laboratories buy GLP-3 (Reta) for in vitro work include triple-receptor binding and cAMP-signaling assays in cells co-expressing GIP, GLP-1 and glucagon receptors, glucose-dependent insulin-secretion studies in pancreatic beta-cell models, energy-expenditure and metabolic-flux research in rodent systems, and comparative dual- versus triple-agonist pharmacology. GLP-3 (Reta) is an investigational compound developed by Eli Lilly and remains in clinical development; it is not an approved medicine.
Every lot, independently verified
Compound information
Chemical & structural reference data — specifications, molecular profile and handling.
GLP-3 (Reta) Mechanism of Action
- Acts as an agonist at three receptors — the GIP receptor, the GLP-1 receptor, and the glucagon receptor — the defining "triple agonist" pharmacology that separates it from single- and dual-incretin compounds.
- Engages Gαs / adenylyl-cyclase / cAMP signaling at each of the three receptors in receptor-expressing cell models.
- Potentiates glucose-dependent insulin secretion through the GIP and GLP-1 incretin arms in pancreatic beta-cell assays.
- Adds glucagon-receptor agonism on top of the dual-incretin mechanism, a contribution implicated in energy-expenditure and lipid-metabolism pathways in preclinical models.
- Carries a fatty-acid acylation that enables reversible serum-albumin binding and a markedly extended half-life relative to native incretin peptides.
- Serves as the reference triple-receptor tool compound for dissecting the relative contribution of GIP, GLP-1 and glucagon signaling in multi-incretin pharmacology.
GLP-3 (Reta) Research Applications
- GIP, GLP-1 and glucagon receptor binding and cAMP-accumulation assays in cells co-expressing the three receptors, where GLP-3 (Reta) is the standard reference triple agonist.
- Glucose-dependent insulin-secretion studies in pancreatic beta-cell models, isolating the incretin contribution to insulinotropic activity.
- Energy-expenditure and metabolic-flux research in rodent systems, probing the glucagon-receptor arm absent from single- and dual-agonist compounds.
- Comparative dual- versus triple-agonist pharmacology, run alongside GLP-1 (Sema) (single) and GLP-2 (Triz) (dual) to dissect receptor-specific effects.
- Albumin-binding and half-life characterization of fatty-acylated incretin analogs.
- Structure-activity studies of triple-receptor incretin peptides and engineered receptor selectivity.
Why Buy GLP-3 (Reta) from Koi Peptides?
- Every batch of Koi GLP-3 (Reta) is synthesized and lyophilized in the United States, then released against independent third-party laboratory (Freedom Diagnostics Testing) testing.
- Each lot is tested by HPLC for purity, LC-MS for identity confirmation, and endotoxin assay for sterility readiness.
- The lot ID is printed on every vial and ties back to a public COA library, so researchers can verify documentation before they buy and after the vial arrives.
- Orders placed before 2 PM CT ship the same business day, and shipping is free on orders over $200.
References
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- Jastreboff, A. M., et al. (2023). Triple–hormone-receptor agonist GLP-3 (Reta) for obesity — a phase 2 trial. New England Journal of Medicine, 389(6), 514–526. doi.org/10.1056/NEJMoa2301972
- Coskun, T., et al. (2022). LY3437943, a novel triple glucagon, GIP, and GLP-1 receptor agonist. Cell Metabolism, 34(9), 1234–1247. doi.org/10.1016/j.cmet.2022.07.013
- Müller, T. D., et al. (2019). Glucagon-like peptide 1 (GLP-1). Molecular Metabolism, 30, 72–130. doi.org/10.1016/j.molmet.2019.09.010
- Rosenstock, J., et al. (2023). GLP-3 (Reta) in people with type 2 diabetes: a phase 2 trial. The Lancet, 402(10401), 529–544. doi.org/10.1016/S0140-6736(23)01053-X
- Knerr, P. J., et al. (2022). Selection and progression of unimolecular agonists at the GIP, GLP-1, and glucagon receptors. Molecular Metabolism, 63, 101533. doi.org/10.1016/j.molmet.2022.101533
- Drucker, D. J. (2018). Mechanisms of action and therapeutic application of GLP-1. Cell Metabolism, 27(4), 740–756. doi.org/10.1016/j.cmet.2018.03.001
Regulatory Status
FDA, WADA anti-doping, and compounding status — provided for research context.
Regulatory Status
GLP-3 (Reta) (LY3437943) is an investigational compound developed by Eli Lilly. It is not approved by the FDA or any other regulatory authority for any indication, and it has been studied in clinical trials for obesity and type 2 diabetes. The research-grade material supplied by Koi Peptides is synthesized independently for in vitro laboratory research only — not formulated, packaged, or labeled for human use, not equivalent to any approved or investigational drug product, and not authorized for any human or veterinary indication.
GLP-3 (Reta) is not currently named on the WADA 2026 Prohibited List. GLP-1 receptor agonists as a class are tracked under the 2026 WADA Monitoring Program, which records patterns of use across sports without imposing sanctions. WADA is expected to evaluate whether to formally prohibit incretin receptor agonists in future cycles. Athletes should maintain documentation for any approved medical use.
Koi Peptides is a chemical research supplier — not a compounding pharmacy or outsourcing facility under sections 503A or 503B of the Federal Food, Drug, and Cosmetic Act — and supplies no compounded preparations of any kind. Because GLP-3 (Reta) is an unapproved investigational molecule, it is not eligible for pharmacy compounding for human use.
For research use only. Not for human or veterinary use. GLP-3 (Reta) is supplied to qualified research professionals for in vitro laboratory study. It has not been evaluated by the FDA and is not intended to diagnose, treat, cure, or prevent any disease. Koi Research Labs LLC is a chemical supplier, not a compounding pharmacy under 503A nor an outsourcing facility under 503B of the Federal Food, Drug, and Cosmetic Act. By purchasing, the buyer agrees this material will not be introduced into humans or animals. Misuse may violate federal, state, or local laws.
Frequently Asked Questions About GLP-3 (Reta)
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