SS-31 10mg

SS-31 is a synthetic aromatic-cationic tetrapeptide, D-Arg-Dmt-Lys-Phe-NH2, from the Szeto-Schiller family of peptides. These peptides cross cell membranes and concentrate at the inner mitochondrial membrane. Contexx Research supplies SS-31 in Canada as a 10 mg lyophilized research peptide with a COA on the page.

SS-31 specifications

Research overview

The Szeto-Schiller peptides were developed by Hazel Szeto and Peter Schiller. In 2004 their group showed that these cell-permeable tetrapeptides accumulate at the inner mitochondrial membrane, where they inhibited mitochondrial swelling and oxidative cell death in isolated mitochondria and cell models, and reduced injury in an ischemia–reperfusion model [1]. Alternating aromatic and basic residues let SS-31 enter cells independently of energy or transporters, even though it carries a 3+ net charge.

Later work identified cardiolipin, the signature phospholipid of the inner mitochondrial membrane, as SS-31’s main binding target. A 2014 paper in the British Journal of Pharmacology describes how SS-31’s interaction with cardiolipin affects cristae structure, electron transport and mitochondrial bioenergetics in experimental systems [2].

A 2025 review summarises SS-31’s structure, mechanism and the main findings from preclinical research [3]. In the laboratory, SS-31 is used in isolated-mitochondria assays, respirometry, cardiolipin-binding studies and as a reference compound in mitochondria-targeted peptide research.

Selected references

1. Zhao K et al. J Biol Chem. 2004. PubMed 15178689
2. Szeto HH Br J Pharmacol. 2014. PubMed 24117165
3. Tung C et al. Int J Mol Sci. 2025. PubMed 39940712

Storage and handling

SS-31 ships as a lyophilized (freeze-dried) powder. Dry material is far more stable than material in solution, so keep it in its dry, sealed state until you need it.

• Store unopened vials of SS-31 at −20 °C, dry and protected from light. Let the vial reach room temperature before opening to limit condensation.
• Prepare stock solutions in a solvent suited to your assay, label them with concentration and date, and keep them at 2–8 °C for short-term use.
• For longer storage of solutions, divide them into single-use aliquots and freeze them; avoid repeated freeze–thaw cycles.
• Handle with gloves and eye protection, following your laboratory’s standard chemical-hygiene practice.

See our guide to storing lyophilized peptides in the lab for more detail.

Quality and testing

A Certificate of Analysis for SS-31 is available through the Check COA button on this page. Review it for the tested identity and purity of the current lot.

We don’t list purity figures in this description; the lot COA is the reference for identity and purity. Researchers should confirm identity and concentration with their own analytical methods where their protocol requires it.

Frequently asked questions

What’s included when I order SS-31 10 mg?

One sealed vial containing 10 mg of SS-31 as a lyophilized powder. Reconstitution solution is sold separately.

Does SS-31 come with a Certificate of Analysis (COA)?

Yes. The lot COA is available through the Check COA button on this page.

How fast is shipping in Canada?

Orders are processed Monday to Friday, and most orders ship within 24 hours from Mississauga, Ontario, in secure, tamper-evident packaging. Orders placed on Friday afternoon (after the 12:00 PM ET cut-off) ship on Monday, when Canada Post resumes pickup, or on the next business day if Monday is a statutory holiday. Once your order ships, delivery typically takes 1–3 business days in Ontario and Quebec and 2–6 business days in the rest of Canada, and a tracking number is emailed to you. Orders over $250 CAD shipped within Canada qualify for free standard shipping. See our Shipping Policy for details.

How should SS-31 be stored?

Store unopened vials at −20 °C, dry and protected from light. After reconstitution, keep solutions at 2–8 °C for short-term use, or freeze single-use aliquots and avoid repeated freeze–thaw cycles.

What does “research use only” mean?

“Research use only” means SS-31 is sold only as a reference material for in-vitro laboratory and analytical research by qualified professionals. It is not for use in humans or animals, not for diagnostic use, and not a drug, natural health product, food, supplement or cosmetic.

Research use only

SS-31 is sold by Contexx Research Inc. strictly as a reference material for in-vitro laboratory research and analytical use by qualified professionals. It is not a drug, natural health product, food, dietary supplement or cosmetic. It is not intended for use in humans or animals, for diagnostic purposes, or for ingestion or any other form of administration to a living organism. Nothing on this page describes or implies any effect in humans or animals. Purchasers are responsible for handling, storage and disposal in line with applicable laws and their institution’s policies. By ordering, you confirm that you are purchasing for legitimate laboratory research and agree to our Terms and Conditions.