Retatrutide (LY3437943) — Certificate of Analysis

Lot RT10-2026-001 of GLP-3 RT assayed at 99.15% peptide purity by RP-HPLC against a ≥95.0% release specification, 4.15 percentage points clear of it. Released 06/05/2026 by ILS Laboratories, ISO/IEC 17025 Accredited. Synthetic 39-residue lipidated peptide acting as a triple GIP/GLP-1/glucagon receptor agonist for metabolic signaling research.

Net peptide content measured 10.57 mg against a 10 mg label — the mass of actual peptide in the vial, as distinct from salts, water and counter-ions. It is reported rather than graded, so it carries no pass/fail.

Full QC panel

Analyte	Specification	Result	Status
Peptide Purity (HPLC)	≥ 95.0%	99.15%	Pass
Identity (HPLC-RTM)	Retatrutide Confirmed	Confirmed	Pass
Net Peptide Content	Report Only	10.57 mg	—
Fentanyl Screen	Immunoassay, 50 ng/mL cutoff	Not Detected	Pass

Sterility & endotoxin

Test	Specification	Result	Status
Sterility (PCR)	No Growth	No Growth	Pass
Endotoxin (USP <85>)	Report Result	0.15 EU/mL	Reported

Endotoxin is reported as a measured value rather than graded pass/fail: acceptable limits depend on route and matrix, and no universal threshold applies to research-use material. The laboratory reports the figure and leaves the judgement to you.

Elemental impurities

Panel	Method	Result	Status
Arsenic, cadmium, chromium, lead, mercury	ICP-MS, USP <233>	5 of 5 under limit	Pass

Per-element measurements are on the signed certificate below and in the laboratory's own record.

Reference data

Property	Value
Compound	Retatrutide (LY3437943)
Also known as	LY3437943, LY-3437943, Retatrutide acetate (salt form), Triple GIP/GLP-1/glucagon receptor agonist
Sequence	YX(Aib)QGTFTSDYSI-X(MeL)-LDKKAQX(Aib)AFIEYLLEGGPSSGAPPPS-NH2 (39 residues; Lys20 bears a C20-diacid-(gamma-Glu)-AEEA side chain; C-terminal serinamide)
Molecular formula	C221H342N46O68
Molecular weight	4731.33 g/mol
CAS number	2381089-83-2
Physical form	Lyophilized powder
Storage	Store lyophilized powder at -20C protected from light and moisture; for long-term storage, -80C is recommended. Once reconstituted, store at 2-8C and use within a limited working period; avoid repeated freeze-thaw cycles.