Retatrutide

Retatrutide research peptide in Thailand

Retatrutide (developmental code LY3437943) is Eli Lilly's investigational triple-receptor agonist, a single peptide that activates the GLP-1, GIP, and glucagon receptors at once and is studied for its effects on body weight, glycaemic control, and hepatic fat metabolism. It sits one step beyond the dual and single incretin agonists that preceded it, which is why metabolic labs use it as a reference triple agonist.

Supplied as a lyophilised powder for laboratory research use only. This page summarises the published literature so a researcher can identify the compound; it is not a medicine and gives no administration guidance.

Quick facts

Product

Retatrutide (LY3437943)

Developer

Eli Lilly (investigational, not approved)

CAS number

2381089-83-2

Molecular weight

~4731 Da (peptide free base, reported)

Intended use

laboratory research use only

How retatrutide works

Retatrutide is a single acylated peptide engineered to switch on three metabolic receptors simultaneously. The GLP-1 and GIP arms behave much like tirzepatide, driving glucose-dependent insulin secretion, slowing gastric emptying, and reducing appetite signalling. What sets retatrutide apart is the added glucagon receptor activity.

In the liver, glucagon signalling raises fatty-acid oxidation and lifts resting energy expenditure, so the compound is studied for its effect on both sides of energy balance, intake and expenditure, rather than intake alone. Because the simultaneous GLP-1 signal offsets glucagon's tendency to raise blood glucose, phase 2 trials reported increased energy expenditure without net loss of glycaemic control.

Key research findings

• In a phase 2 obesity trial (338 adults, 48 weeks), the 12 mg dose group showed a least-squares mean body-weight change of −24.2% versus −2.1% for placebo, with 83% of that group reaching at least 15% reduction (Jastreboff et al., NEJM 2023, PMID 37366315).
• In a phase 2 type 2 diabetes trial, retatrutide produced dose-dependent HbA1c reductions up to roughly −2.0% and body-weight reductions near −17% at the 12 mg escalation, exceeding both placebo and the dulaglutide comparator (Rosenstock et al., Lancet 2023, PMID 37385280).
• Across both phase 2 programmes the adverse events reported were predominantly mild-to-moderate gastrointestinal effects, with no severe hypoglycaemia and no deaths recorded in the diabetes cohort (Rosenstock et al., Lancet 2023, PMID 37385280).

Research applications

• Triple-receptor (GLP-1 / GIP / glucagon) pharmacology and additive receptor-engagement studies.
• Energy-expenditure and thermogenesis pathway investigations, contrasting intake- versus expenditure-driven effects.
• Hepatic lipid metabolism and metabolic-dysfunction-associated steatotic liver disease (MASLD/NASH) models.
• Comparative efficacy modelling against dual and single incretin agonists such as tirzepatide and semaglutide.
• Glycaemic-control and insulin-sensitivity studies in metabolic disease models.
• Substrate-utilisation and metabolic-flexibility research.

Dosing in the literature

Phase 2 trials escalated across that range in roughly 4-week steps, from 1 mg to 12 mg. These figures summarise what published trials reported and are provided for literature reference only, not as administration guidance. To model concentrations and volumes for a study, use the peptide calculator.

Reconstitution & storage

Solvent

Bacteriostatic water — the common laboratory choice

Mixing

Add solvent down the vial wall and swirl gently until dissolved; do not shake

Storage

Refrigerate at 2–8 °C after reconstitution

Use within

About 28 days once reconstituted

Freeze / light

Keep lyophilised powder frozen or refrigerated; protect from direct light; avoid repeated freeze–thaw

These are standard laboratory handling conventions, not instructions for use. See bacteriostatic water for the standard diluent. In Thailand's heat and humidity, minimise time at room temperature.

Selected research

• Triple-Hormone-Receptor Agonist Retatrutide for Obesity — A Phase 2 Trial — New England Journal of Medicine, 2023 (PMID 37366315).
• Retatrutide, a GIP, GLP-1 and glucagon receptor agonist, for people with type 2 diabetes: a phase 2 trial — The Lancet, 2023 (PMID 37385280).
• Further indexed literature via PubMed search for retatrutide.

Related compounds

• Semaglutide — single GLP-1 agonist; the baseline of the incretin family and a common comparison point in metabolic research. Tirzepatide (dual GLP-1 / GIP) sits between the two but is not currently in our catalog.
• Bacteriostatic water — the standard diluent used to reconstitute lyophilised research peptides.

See also: retatrutide vs semaglutide vs tirzepatide and the retatrutide Thailand research guide.

Retatrutide FAQ

Compliance note

Retatrutide is provided for laboratory research use only. It is not intended for human or veterinary use, and it is not intended to diagnose, treat, cure, or prevent any disease. Trial results described on this page are findings of the specific cited studies, not claims about this product.