SS-31 10mg
10mg per vial — Lyophilized Powder
Coming soon — use the Notify me button to get an email as soon as the first lot is in stock.
Description
SS-31 is a synthetic tetrapeptide with the sequence D-Arg-2',6'-dimethyl-Tyr-Lys-Phe-NH2. The letters SS stand for Szeto-Schiller, after Hazel Szeto and Peter Schiller, whose laboratories developed this family of small, cell-permeable, aromatic-cationic peptides. Several members of the family, SS-31 among them, were found to cross cell membranes and concentrate in mitochondria.
SS-31 alternates basic and aromatic residues and carries a net positive charge of +3 at neutral pH. According to published studies, the peptide accumulates at the inner mitochondrial membrane independently of membrane potential and binds cardiolipin through electrostatic and hydrophobic interactions. Cardiolipin is an anionic phospholipid concentrated in that membrane and closely tied to the assembly and stability of the electron transport chain complexes. This cardiolipin interaction is the main reason SS-31 is described as a mitochondria-targeted research peptide.
In cell and animal models, SS-31 has been studied for its relationship to mitochondrial membrane organization, electron transport chain function, and markers of oxidative stress. Published research spans models of ischemia-reperfusion, age-related mitochondrial decline, and cellular bioenergetics, examining how the peptide's interaction with cardiolipin relates to respiratory-chain function and reactive oxygen species production under experimental conditions.
These findings describe research settings; they are not claims about this product, which is supplied only as a reference material for laboratory research.
Pepspan's SS-31 is supplied as a white lyophilized powder, 10mg per vial, with a purity specification of ≥98% by HPLC. The first lot will be analysed by an independent laboratory and the certificate will be published on its lot page.
Handling & Storage
SS-31 is supplied lyophilized; for laboratory work it is dissolved in a suitable sterile aqueous solvent under aseptic conditions — swirl gently, do not shake.
- Expected appearance: Clear, colourless, particulate-free solution.
- After reconstitution: Store at 2-8°C protected from light. Prepare aliquots to avoid repeated freeze-thaw cycles.
Composition
- Peptide: SS-31 (D-Arg-Dmt-Lys-Phe-NH2)
- Sequence: D-Arg-2',6'-Dmt-Lys-Phe-NH2 (Dmt = 2',6'-dimethyl-L-tyrosine)
- Length: 4 amino acids (tetrapeptide), C-terminal amidation
- Molecular Formula: C32H49N9O5
- Molecular Weight: 639.8 g/mol
- Purity: ≥98% (HPLC, specification)
- Appearance: White lyophilized powder
- Quantity: 10mg per vial
Storage
- Store the lyophilized peptide at -20°C for long-term storage.
- For short-term storage, refrigerate at 2-8°C.
- After reconstitution, store at 2-8°C protected from light.
- Avoid repeated freeze-thaw cycles.
- Protect from light and moisture at all times.
Certificate of Analysis
The first lot of SS-31 sold by Pepspan will be analysed by an independent laboratory for HPLC purity and the actual content per vial. The certificate will be published on the lot page, and every later lot will be tested the same way.
Batch Purity Report
Independent lab — tested on arrivalCurrent Batch: awaiting first delivery
Every lot of SS-31 will be tested by an independent laboratory: HPLC purity and the actual content per vial. Reports are lot-specific — not generic.
View All Purity Reports →Research Disclaimer
This product is intended for laboratory research use only. It is not a drug, food, cosmetic, or dietary supplement. Pepspan's SS-31 is not approved for human or veterinary use by any regulatory agency in the EU or US. It must not be administered to humans or animals outside of approved clinical trials. By purchasing this product, you confirm that you are a qualified researcher and that this product will be used exclusively for legitimate scientific research purposes. Pepspan assumes no liability for any misuse of this product. All handling must comply with local regulations and institutional safety protocols.
Frequently Asked Questions
What is SS-31?
SS-31 is a synthetic tetrapeptide, D-Arg-2',6'-dimethyl-Tyr-Lys-Phe-NH2, also referred to in the literature as Szeto-Schiller peptide 31. It is a small, aromatic-cationic peptide studied for its ability to concentrate in the inner mitochondrial membrane and associate with cardiolipin.
How does SS-31 interact with mitochondria?
SS-31 alternates basic and aromatic residues and carries a net positive charge of +3 at neutral pH. Published studies report that it accumulates at the inner mitochondrial membrane independently of membrane potential and binds cardiolipin, an anionic phospholipid linked to the organization of the electron transport chain, through electrostatic and hydrophobic interactions. This binding is the basis for its use as a mitochondria-targeted research tool in cell and animal models.
What research areas cite SS-31?
Published research on SS-31 covers mitochondrial membrane organization, electron transport chain function, and oxidative-stress markers, in models of ischemia-reperfusion, age-related mitochondrial decline, and cellular bioenergetics. Researchers should consult the primary literature for the models and conditions reported in each study.
How should SS-31 be stored?
Store the lyophilized vial at -20°C for long-term storage, or at 2-8°C for short periods, protected from light and moisture. After reconstitution under aseptic laboratory conditions, keep the solution at 2-8°C protected from light and avoid repeated freeze-thaw cycles.
When will SS-31 be available at Pepspan?
SS-31 is coming soon. Use the Notify me button on this page to receive an email as soon as the first lot is in stock; its independent analysis will be published on the lot page.
Do I need a prescription for SS-31?
Pepspan does not sell medicines and does not dispense against prescriptions. SS-31 is supplied exclusively as a reference material for laboratory research, not for human or veterinary use. Rules for research peptides differ by country; check your local regulations before ordering.
Where can I buy SS-31 in Europe?
Pepspan will supply SS-31 10mg lyophilized vials from its stock in Spain, with tracked delivery in 1–3 business days in Spain, 3–5 in Germany, and usually 2–5 across the rest of the EU, plus free shipping on orders from €50. It is not in stock yet: leave your email with the Notify me button and you will be told as soon as it is available. Research use only.
Further Research Resources
Additional research articles, comparison guides, and laboratory protocols related to this product:


