What is Retatrutide? A Complete Research Guide to the Triple Agonist
By Peptura Research Team/7 May 2026/8 min read
The Compound at a Glance
Retatrutide is a synthetic triple receptor agonist peptide from Eli Lilly that activates three targets at once: the glucose-dependent insulinotropic polypeptide receptor (GIPR), the glucagon-like peptide-1 receptor (GLP-1R), and the glucagon receptor (GCGR). It ranks today among the most actively researched compounds in metabolic and incretin biology.
UK researchers can obtain Retatrutide 10mg, Retatrutide 20mg, or Retatrutide 30mg from Peptura at 99.6% HPLC purity with full third-party batch documentation.
Inside the Triple-Agonist Mechanism
The defining feature is simultaneous action at three distinct metabolic receptors. GLP-1 receptor activity feeds into glucose-dependent insulin secretion and central appetite signalling. GIP receptor agonism modulates both insulin and glucagon secretion in glucose-dependent settings. Glucagon receptor agonism reaches hepatic glucose output and energy-expenditure pathways.
Bringing all three together in one molecule creates a research tool with no real precedent. Earlier compounds reached single-receptor (Semaglutide) or dual-receptor (Tirzepatide) activity, but none combined triple activity in a single peptide.
Molecular Properties
Retatrutide carries the molecular formula C₂₂₅H₃₄₈N₄₈O₆₈ and a molecular weight of 4767.4 g/mol. It is supplied as lyophilised powder to be reconstituted with bacteriostatic water before laboratory use. In lyophilised form it stays stable for up to 24 months at -20°C; once reconstituted, keep the solution at 2-8°C and use within four weeks.
Where It Stands Clinically
Retatrutide is in Phase 3 clinical investigation with Eli Lilly. Its Phase 2 data, published in the New England Journal of Medicine in 2023, reported substantial body-weight reductions over 48 weeks across several dosing cohorts. No regulator, the MHRA and FDA included, has approved it for human use. All research belongs in controlled in-vitro laboratory settings.
Research Applications
Retatrutide appears across models of glucose homeostasis, lipid metabolism, energy expenditure, body composition, and appetite regulation. Its triple mechanism makes it particularly well suited to studying crosstalk between incretin and glucagon signalling, a question that single or dual agonists cannot fully answer.
The glucagon arm has drawn especially keen interest, since it engages hepatic and thermogenic pathways that GLP-1 or GIP-targeted compounds leave untouched.
Reconstitution and Handling
Bring the Retatrutide vial and the bacteriostatic water to room temperature, then wipe both stoppers with an alcohol swab. Run the bacteriostatic water slowly down the inner wall of the Retatrutide vial, never straight onto the powder, and swirl gently until dissolved. Do not shake or vortex. Store the reconstituted solution at 2-8°C and use within four weeks. Our complete reconstitution guide has the full protocol.
Sourcing Retatrutide in the UK
Peptura supplies research-grade Retatrutide 10mg, Retatrutide 20mg, and Retatrutide 30mg at 99.6% HPLC purity, batch PEP-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.
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Disclaimer: This article is for research and educational purposes only. All information provided is not intended as medical advice. Peptura products are not for human consumption and are sold strictly for laboratory research use only.