Retatrutide

What Is Retatrutide?

Retatrutide (CAS 2381089-83-2; also known as LY3437943) is a 39-amino acid synthetic peptide engineered as a triple agonist of three distinct metabolic receptors: glucose-dependent insulinotropic polypeptide (GIP), glucagon-like peptide-1 (GLP-1), and glucagon (GCG). Its structure carries a C-20 fatty diacid conjugated to the peptide backbone, extending the plasma half-life to support once-weekly dosing regimens in research protocols. CertaPeptides supplies retatrutide in lyophilized powder form from 2mg through 60mg per vial.

CAS: 2381089-83-2. Alternate identifier: LY3437943. Molecular weight: 4703.5 g/mol. Receptor-engagement profile: GIP-R, GLP-1R, and GCG-R simultaneously.

What Published Clinical Research Has Reported

The trial figures below are direct attributions to peer-reviewed clinical trial publications. They describe outcomes measured in specific trial populations under specific protocols, and are reported here for research context only. They are not claims about what CertaPeptides' research compound will do in any individual.

Body composition — Phase 2 obesity trial (Jastreboff et al., 2023)

Jastreboff et al. (2023) reported, in a Phase 2, 48-week, placebo-controlled trial of 338 adults with obesity (BMI ≥30, or ≥27 with an obesity-related comorbidity) and without diabetes, a mean percent change in body weight at week 48 of −24.2% in the retatrutide 12 mg once-weekly group versus −2.1% in the placebo group. The 8 mg and 12 mg groups both exceeded a mean change of −22%. Source: New England Journal of Medicine, 2023;389(6):514–526. PMID 37366315.

Type 2 diabetes — TRIUMPH Phase 2 (Rosenstock et al., 2023)

Rosenstock et al. (2023) reported, in a 36-week randomised Phase 2 trial of 281 adults with type 2 diabetes, that retatrutide produced dose-dependent mean HbA1c changes from baseline of up to −2.02 percentage points at the 12 mg dose versus −0.01 percentage points in the placebo group, along with mean body weight changes of −16.9% versus −3.0% respectively. Source: The Lancet, 2023;402(10401):529–544. PMID 37385280.

Within the Incretin Class — How Retatrutide Differs

Retatrutide is studied alongside two other research peptides in the same metabolic class: semaglutide (single GLP-1R agonist) and tirzepatide (dual GIP/GLP-1R agonist). The three differ structurally and mechanistically in ways that shape how each compound is studied:

The glucagon-receptor arm is the distinguishing feature: neither semaglutide nor tirzepatide activates GCG-R. In research contexts this is of interest because glucagon agonism increases hepatic glucose output and thermogenesis, adding an energy-expenditure component not present in the single- or dual-agonist compounds. Researchers comparing the three frequently reference the GLP-1 class comparison overview and the molecular-level triple-receptor mechanism overview.

Research Areas Where Retatrutide Is Studied

• GIP, GLP-1, and glucagon receptor pharmacology — comparative in vitro binding and signalling assays
• Preclinical metabolic models of body composition and energy expenditure
• Comparative studies against single- and dual-agonist compounds (semaglutide, tirzepatide)
• Lipid metabolism and hepatic glucose-output pathways (glucagon-arm specific)
• Formulation and stability research for long-acting peptide analogues

Specifications

Storage

Lyophilized powder: −20°C for long-term storage. 2–8°C for short-term use before reconstitution.

Reconstituted: 2–8°C, use within 4 weeks. Do not freeze after reconstitution.

Quality Assurance

• HPLC analysis confirms 99.3% avg purity on every batch
• Mass spectrometry verifies molecular identity
• Certificate of Analysis (COA) included with every order — view sample COAs
• EU-based quality control under CERTALAB S.R.L.

Important Notice — Research Use Only

Retatrutide is supplied by CertaPeptides strictly as a laboratory research compound. The clinical-trial figures cited above are taken from peer-reviewed human clinical trials published in NEJM and The Lancet, and are reported here for research context only. They are not medical claims and do not describe what CertaPeptides' research material will do in any individual. This product is not a drug, not a dietary supplement, not a cosmetic, and not approved by the FDA, EMA, or any other regulatory authority for over-the-counter sale for human or veterinary use. It is not intended to diagnose, treat, cure, prevent, or mitigate any disease or condition. For laboratory research purposes only. Not for human consumption.