Retatrutide Research Peptide (30 mg and 60 mg Vials)

What is retatrutide?

Retatrutide (LY3437943) is an investigational 39-residue peptide developed by Eli Lilly that acts as an agonist at three receptors: GIP, GLP-1 and glucagon. PEPTYVA supplies it as one product in 30 mg and 60 mg vials for laboratory research use only. It is not an approved medicine in any country.

The FDA Global Substance Registration System describes its sequence with two Aib residues, an alpha-methyl leucine and a lysine linked to a C20 fatty diacid through a gamma-glutamyl and short ethylene glycol spacer.

How is retatrutide studied in research?

Retatrutide is studied as a triple hormone receptor agonist. Its three-receptor profile makes it a reference compound for comparing single (GLP-1), dual (GIP and GLP-1) and triple (GIP, GLP-1 and glucagon) receptor agonism in one molecular family.

• Targets: GIP, GLP-1 and glucagon receptors
• Structure: 39 residues, C-terminal amide, C20 fatty diacid on lysine 17
• Typical research topics: receptor pharmacology, glycemic regulation, body weight regulation in controlled studies

What does the current evidence show?

Controlled human studies exist, and the molecule remains investigational. A phase 2 trial (New England Journal of Medicine, 2023) randomized 338 adults with obesity, or with overweight and a weight-related condition, to retatrutide or placebo for 48 weeks. Gastrointestinal events were the most common adverse events, and heart rate increases peaked at 24 weeks and declined afterward.

The phase 3 TRIUMPH-1 trial (New England Journal of Medicine, 2026) randomized 2,339 adults with obesity and without diabetes for 80 weeks, with body weight, knee osteoarthritis pain and sleep apnea endpoints. It met its primary endpoints, and gastrointestinal events were again the most common adverse events. In July 2026 Eli Lilly reported that five phase 3 studies had met their primary endpoints.

How does retatrutide differ from tirzepatide?

Tirzepatide activates GIP and GLP-1 receptors and is approved within branded medicines. Retatrutide adds glucagon receptor activity and has no approval. Both are 39-residue acylated peptides that share the same C-terminal segment, Gly-Gly-Pro-Ser-Ser-Gly-Ala-Pro-Pro-Pro-Ser, which makes them close comparators in receptor research.

Why are 30 mg and 60 mg listed as one product?

The two strengths are variants of the same product. The molecule and specifications do not change; only the amount per vial differs. Each vial label shows its strength, lot number and expiry date.

How is each retatrutide vial documented?

Each vial is linked to its Certificate of Analysis by the PEPTYVA lot number. A COA typically reports identity by mass spectrometry, purity by HPLC, appearance and test dates. Because retatrutide is investigational and has no approved reference product, lot-level identity data are the main way to confirm what the vial contains.

What is the regulatory status of retatrutide?

Retatrutide is not approved by the FDA, COFEPRIS or any other regulator. Eli Lilly stated in July 2026 that it plans to submit retatrutide for US approval in the first quarter of 2027. This PEPTYVA vial is research material only, and any future approval would belong to the sponsor's branded product.

Documentation

Each vial carries a PEPTYVA lot number, strength and expiry date. The Certificate of Analysis for that lot can be requested through our contact page and typically lists identity, purity, appearance and test dates. See Quality & Documentation for how to read a COA.

Storage and handling

Keep the unopened vial sealed in its original packaging, protected from light and heat, at the storage temperature printed on the PEPTYVA label. Check the strength, lot number and expiry date on arrival, and do not use material past the expiry date shown on the label.