What is Retatrutide? Complete Research Guide
By UK Peptide Lab Research Team•7 May 2026•8 min read
What is Retatrutide?
Retatrutide is a synthetic triple receptor agonist peptide developed by Eli Lilly that simultaneously activates the glucose-dependent insulinotropic polypeptide receptor (GIPR), the glucagon-like peptide-1 receptor (GLP-1R), and the glucagon receptor (GCGR). It is currently one of the most actively researched compounds in metabolic and incretin biology.
Researchers sourcing the compound in the UK can purchase Retatrutide 10mg, Retatrutide 20mg, or Retatrutide 30mg from UK Peptide Lab with 99.6% HPLC purity and full third-party batch documentation.
Triple-Agonist Mechanism
Retatrutide's defining feature is its simultaneous activity at three distinct metabolic receptors. GLP-1 receptor activation contributes to glucose-dependent insulin secretion and central appetite signalling. GIP receptor agonism modulates both insulin and glucagon secretion in glucose-dependent contexts. Glucagon receptor agonism influences hepatic glucose output and energy expenditure pathways.
The combination of all three mechanisms in a single molecule creates a research tool with no direct precedent, earlier compounds achieved single (Semaglutide) or dual (Tirzepatide) receptor activity but not triple activity in one peptide.
Molecular Properties
Retatrutide has the molecular formula C₂₂₅H₃₄₈N₄₈O₆₈ and a molecular weight of 4767.4 g/mol. It is supplied as lyophilised powder requiring reconstitution with bacteriostatic water before use in laboratory protocols. The compound is stable for up to 24 months at -20°C in lyophilised form, and reconstituted solution should be stored at 2-8°C and used within 4 weeks.
Current Clinical Status
Retatrutide is currently in Phase 3 clinical investigation by Eli Lilly. Phase 2 data published in the New England Journal of Medicine in 2023 reported substantial body weight reductions over 48 weeks across multiple dosing cohorts. It is not approved for human use by any regulatory authority including the MHRA or FDA. All research must be conducted in controlled in-vitro laboratory settings.
Research Applications
Retatrutide is studied across glucose homeostasis, lipid metabolism, energy expenditure, body composition, and appetite regulation models. Its triple mechanism makes it particularly useful for studying receptor crosstalk between incretin and glucagon signalling pathways, a research area that single- or dual-agonist molecules cannot fully address.
The glucagon receptor activity in particular has generated significant research interest because it engages hepatic and thermogenic pathways not activated by GLP-1- or GIP-targeted compounds.
Laboratory Handling and Reconstitution
Allow the Retatrutide vial and bacteriostatic water vial to reach room temperature. Sterilise both stoppers with an alcohol swab. Slowly inject bacteriostatic water down the inner wall of the Retatrutide vial, never directly onto the lyophilised powder, then gently swirl until fully dissolved. Never shake or vortex. Store the reconstituted solution at 2-8°C and use within 4 weeks. See our complete reconstitution guide for protocol details.
Sourcing Retatrutide in the UK
UK Peptide Lab supplies research-grade Retatrutide 10mg, Retatrutide 20mg, and Retatrutide 30mg with 99.6% HPLC purity, batch UKPL-742, third-party tested, with same-day UK dispatch on orders before 2pm GMT and free Royal Mail Tracked shipping over £45. Supplied for in-vitro laboratory research only.
Related Products
Disclaimer: This article is for research and educational purposes only. All information provided is not intended as medical advice. UK Peptide Lab products are not for human consumption and are sold strictly for laboratory research use only.