What is the amino acid sequence of retatrutide?

Retatrutide is a research peptide whose amino acid sequence is on the public registry record. The full published sequence is listed below; it includes non-standard residues and side-chain modifications as written in the source record. Its molecular formula is C221H342N46O68. Its molecular weight is 4731.3 g/mol.

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)

Class. peptide (lipidated).

Formula. C221H342N46O68.

Mass. 4731.3 g/mol.

Analytical note. Identity confirmation by mass spectrometry uses the mass calculated from the 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.

Synonyms	LY3437943 (pubchem.ncbi.nlm.nih.gov)
Compound class	peptide (lipidated) (pubchem.ncbi.nlm.nih.gov)
Storage (lyophilised)	-20 °C, dry, protected from light (sigmaaldrich.com)

Sizes and prices at Sable

Vial	Price	Per mg	UK same-size check (2026-10-16)
5 mg	£16.93	£3.39	lowest other £20.95 across 2 UK sellers
10 mg	£24.99	£2.50	lowest other £51.99 across 2 UK sellers
15 mg	£37.99	£2.53	lowest other £85.00 across 1 UK sellers
20 mg	£48.99	£2.45	lowest other £93.99 across 2 UK sellers
30 mg	£66.99	£2.23	lowest other £85.00 across 4 UK sellers
40 mg	£88.99	£2.22	no same-size match
50 mg	£108.99	£2.18	no same-size match
60 mg	£128.99	£2.15	no 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 column	C18 reversed-phase (300 A pore, C4/C8 suitable for large/lipidated)
Mobile phase	A: water + 0.1% TFA; B: acetonitrile + 0.1% TFA; linear gradient (e.g. 5-65% B over 20-30 min)
Detection	214-220 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.

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.

Compound	Lyophilised storage	Light / notes
Retatrutide	-20 C long term (-80 C acceptable), sealed and desiccated; 2-8 C for weeks	protect 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.

Compound	HPLC column / detection	MS / expected ion
Retatrutide	C18 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.