SS-31 (Elamipretide)

Description

What is SS-31?

SS-31, also called elamipretide, is a synthetic tetrapeptide (D-Arg-Dmt-Lys-Phe-NH2) with a molecular weight of 639.8 g/mol as the free base. An elamipretide drug, Forzinity, was FDA-approved in September 2025. Peptryn’s 50mg vial is a laboratory research material and is not that product.

SS-31 specifications

Compound	SS-31 (elamipretide)
Size	50mg
Form	Lyophilized powder
Molecular weight	639.8 g/mol (free base)
Formula	C32H49N9O5 (free base)
CAS number	736992-21-5
Solubility	Water-soluble

Lot testing and COA

The latest published report is for lot 2026-08-05: 99.75% purity by HPLC-UV-MS and a negative endotoxin result, tested by MZ Biolabs. The certificate links to the laboratory’s own report, so you can check it without relying on us.

SS-31 50mg COA · COA Library

Ordering

Orders placed on peptryn.com ship from the USA with same-day dispatch, and shipping is free on orders over $150. For a question about a lot or a size, email [email protected].

Storage

Store lyophilized powder at -20°C, protected from light and repeated freeze-thaw cycles.

Frequently asked questions

What is SS-31?

SS-31, also called elamipretide, is a synthetic tetrapeptide, about 640 Da as the free base. Peptryn supplies it as a 50mg lyophilized laboratory material.

What purity is Peptryn’s SS-31?

Peptryn’s SS-31 is verified at 99.75% purity by HPLC-UV-MS, tested by MZ Biolabs (lot 2026-08-05). Read the COA. HPLC purity is area percent, the share of the main peak among all detected peaks; see our guide to peptide purity for what that means.

How is SS-31 stored?

Store lyophilized powder at -20°C, protected from light and repeated freeze-thaw cycles.

What is SS-31’s CAS number?

SS-31’s CAS number is 736992-21-5. Molecular weight: 639.8 g/mol (free base).

Is SS-31 for human use?

No. Peptryn sells it for laboratory research only, and it is not approved for human or veterinary use. We do not give dosing or administration guidance.

Is SS-31 the same as elamipretide?

SS-31 and elamipretide are the same compound. Forzinity, an FDA-approved elamipretide drug, was approved in September 2025. Peptryn’s SS-31 vial is a laboratory research material and is not that product.

Is SS-31 the same as MOTS-c?

No. Both are studied in mitochondrial research but are different peptides. SS-31 (elamipretide) is a synthetic tetrapeptide, about 640 Da. MOTS-c is a 16-amino-acid peptide encoded in mitochondrial DNA, about 2,175 Da. Peptryn sells both.

Related: SS-31 peptide guide · What is a COA? · Peptide testing · Popular peptides

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For laboratory research use only. Not for human or veterinary use, and not a drug, food, dietary supplement or cosmetic. You must be 21 or older to buy.