Research use only · Lyophilised material · Not a medicine · Not for human or veterinary use · Disclaimer

What is the molecular formula of retatrutide?

Retatrutide has the molecular formula C221H342N46O68. The corresponding molecular weight is 4731.3 g/mol. CAS Registry Number 2381089-83-2. Synonyms include LY3437943. The expected mass for identity confirmation by mass spectrometry is derived from this formula. Sable's release specification is ≥99% by HPLC with identity confirmed against the expected mass.

Formula. C221H342N46O68.

Sequence. H-Tyr-Aib-Gln-Gly-Thr-Phe-Thr-Ser-Asp-Tyr-Ser-Ile-αMeLeu-Leu-Asp-Lys-Lys(N6-{2-[2-(2-{[N-(19-carboxynonadecanoyl)-L-γ-glutamyl]amino}ethoxy)ethoxy]acetyl})-Ala-Gln-Aib-Ala-Phe-Ile-Glu-Tyr-Leu-Leu-Glu-Gly-Gly-Pro-Ser-Ser-Gly-Ala-Pro-Pro-Pro-Ser-NH2 (Lys side chain as named in WHO Proposed INN List 128, WHO Drug Information Vol. 36 No. 4, 2022, p. 1051)

Analytical note. The expected mass for identity confirmation by mass spectrometry is derived from this formula. Sable's release specification is ≥99% by HPLC with identity confirmed against the expected mass (quality page). Research use only. Not a medicine. Not for human or veterinary use.

Sources

Retatrutide: reference facts

3 Retatrutide values, each linked to its public source; see the Retatrutide reference page.

SynonymsLY3437943 (pubchem.ncbi.nlm.nih.gov)
Compound classpeptide (lipidated) (pubchem.ncbi.nlm.nih.gov)
Storage (lyophilised)-20 °C, dry, protected from light (sigmaaldrich.com)

Sizes and prices at Sable

VialPricePer mgUK same-size check (2026-10-16)
5 mg£16.93£3.39lowest other £20.95 across 2 UK sellers
10 mg£24.99£2.50lowest other £51.99 across 2 UK sellers
15 mg£37.99£2.53lowest other £85.00 across 1 UK sellers
20 mg£48.99£2.45lowest other £93.99 across 2 UK sellers
30 mg£66.99£2.23lowest other £85.00 across 4 UK sellers
40 mg£88.99£2.22no same-size match
50 mg£108.99£2.18no same-size match
60 mg£128.99£2.15no same-size match

Multi-vial pricing on the same item: 3+ vials 10% off, 5+ vials 15% off, 10+ vials 20% off. Every lot has a certificate of analysis: CoA library.

Typical analytical method

HPLC columnC18 reversed-phase (300 A pore, C4/C8 suitable for large/lipidated)
Mobile phaseA: water + 0.1% TFA; B: acetonitrile + 0.1% TFA; linear gradient (e.g. 5-65% B over 20-30 min)
Detection214-220 nm (peptide bond) and 280 nm (Trp/Tyr present)

General literature method. The lot CoA records the method actually used. How to read an HPLC chromatogram.

Related questions

Lyophilised storage on file: Retatrutide

From the Sable storage reference (lyophilised material only; temperature, light, moisture). Literature basis is linked per row. See peptide storage.

CompoundLyophilised storageLight / notes
Retatrutide-20 C long term (-80 C acceptable), sealed and desiccated; 2-8 C for weeksprotect from light; no specific sequence liabilities identified from sequence data on file (source)

Typical analytical method: Retatrutide

Reference HPLC and MS conditions from the Sable analytical-methods file; a lot's CoA states the method actually used. See how to read a CoA.

CompoundHPLC column / detectionMS / expected ion
RetatrutideC18 reversed-phase (300 A pore, C4/C8 suitable for large/lipidated); 214-220 nm (peptide bond) and 280 nm (Trp/Tyr present)ESI-MS (positive mode); LC-MS for identity; [M+3H]3+ ~1578.1; [M+4H]4+ ~1183.8; [M+5H]5+ ~947.3; [M+6H]6+ ~789.6

Research use only. Not a medicine. Not for human or veterinary use.