What is SS-31 (Elamipretide)?
SS-31 (also referred to as Elamipretide or MTP-131) is a cell-permeable tetrapeptide with the sequence D-Arg-Dmt-Lys-Phe-NH₂ (where Dmt is 2',6'-dimethyltyrosine). It belongs to the Szeto-Schiller (SS) peptide series developed by Dr. Hazel Szeto at Cornell University and is the most clinically advanced compound in this class.
SS-31's defining characteristic is its selective concentration at the inner mitochondrial membrane (IMM) through electrostatic and hydrophobic interaction with cardiolipin — a tetra-acyl phospholipid that is unique to the IMM and serves as a critical structural and functional scaffold for the electron transport chain complexes. Cardiolipin peroxidation under oxidative stress conditions is associated with disruption of respiratory chain supercomplex architecture and increased cytochrome c release — a key step in apoptotic signalling.
By binding cardiolipin and reducing its peroxidation by reactive oxygen species, SS-31 is studied for its capacity to preserve electron transport chain function, reduce mitochondrial ROS production, and maintain membrane potential under conditions of mitochondrial dysfunction. ClaraScience supplies SS-31 in 10mg vials, HPLC-tested to ≥99.0% purity. For laboratory research use only.
Mechanism. Cardiolipin binding at the inner mitochondrial membrane — preserves ETC function and reduces ROS production.
Clinical stage. Phase II/III trials completed for HFpEF, Barth syndrome, and mitochondrial myopathy.
Sequence. D-Arg-Dmt-Lys-Phe-NH₂ (cell-permeable tetrapeptide, 640.77 g/mol).
Research Background
The foundational SS peptide research was published by Szeto et al. in the AAPS Journal (2006;8:E277–E283), characterising the cellular uptake, mitochondrial targeting, and antioxidant properties of the SS peptide series. Subsequent work has demonstrated SS-31's utility across a broad range of mitochondrial dysfunction models including ischaemia-reperfusion injury, cardiomyopathy, renal tubular injury, and neurodegenerative models.
Stealth BioTherapeutics conducted a substantial Phase II/III clinical programme under the Elamipretide name. The PROGRESS trial investigated elamipretide in HFpEF — a major unmet medical need where mitochondrial dysfunction in cardiomyocytes is implicated in disease pathophysiology. Barth syndrome trials provided evidence of safety and target engagement in a genetically defined mitochondrial cardiopathy. Phase III primary mitochondrial myopathy trials were also conducted.
While Elamipretide has not achieved regulatory approval, the clinical dataset represents one of the most extensive human pharmacokinetic and safety databases for any mitochondria-targeted peptide, making SS-31 a well-characterised tool for preclinical research. It is frequently studied alongside MOTS-C and NAD+ in mitochondrial biology research programmes.
Key citation Szeto HH. "Mitochondria-targeted cytoprotective peptides for ischemia-reperfusion injury." AAPS J. 2006;8(3):E521–E531. Also: Szeto HH, AAPS J 2006;8:E277–E283.
Compound Specifications
| Common Name |
SS-31 · Elamipretide · MTP-131 |
| Sequence |
D-Arg-Dmt-Lys-Phe-NH₂ |
| Molecular Weight |
640.77 g/mol |
| Target |
Cardiolipin (inner mitochondrial membrane) |
| Purity (HPLC) |
≥99.0% — independently verified |
| Vial Size |
10mg lyophilised powder |
| Storage |
2–8°C (short-term) · −20°C (long-term) |
| Primary Reference |
Szeto HH, AAPS J 2006;8:E277–E283 |
Storage & Handling
- Unopened vial: 2–8°C for regular use; −20°C for longer-term storage.
- After reconstitution: 2–8°C, use within 28 days. Avoid freeze-thaw cycles.
- Reconstitution: Sterile bacteriostatic water. Use our free reconstitution calculator.
Full protocols: Storage & Handling Guide.
Ordering & Pricing — Australia
| Quantity |
Price per vial |
Saving |
| 1–4 vials |
$89.95 AUD |
— |
| 5–9 vials |
$79.95 AUD |
Save 11% |
| 10+ vials |
$74.95 AUD |
Save 17% |
Free priority tracked shipping on orders over $250 AUD. Dispatched within 24 hours. Wholesale enquiries welcome.
Frequently Asked Questions
What is SS-31?
SS-31 (Elamipretide, D-Arg-Dmt-Lys-Phe-NH₂) is a cell-permeable tetrapeptide that selectively concentrates at the inner mitochondrial membrane via cardiolipin binding. It has been studied in Phase II/III clinical trials for mitochondrial dysfunction. For laboratory research use only.
What is cardiolipin?
Cardiolipin is a unique tetra-acyl phospholipid found almost exclusively in the inner mitochondrial membrane, where it plays a critical structural role in maintaining the architecture of respiratory chain supercomplexes. Cardiolipin peroxidation is a key marker of mitochondrial dysfunction and a trigger for cytochrome c release and apoptotic signalling.
How is SS-31 different from MOTS-C?
MOTS-C is a mitochondria-encoded peptide that translocates to the nucleus to activate AMPK signalling. SS-31 stays at the inner mitochondrial membrane, where it reduces cardiolipin peroxidation and preserves electron transport chain efficiency. The two compounds act on different aspects of mitochondrial biology.
Is SS-31 approved by the FDA or TGA?
No. Elamipretide/SS-31 has not been approved by the FDA, TGA, or any major regulatory authority. Phase III trials have been conducted but therapeutic approval has not been granted. ClaraScience supplies it for laboratory research use only.
Is SS-31 available in Australia?
ClaraScience stocks SS-31 (Elamipretide) in our Australian warehouse. 10mg vials, dispatched within 24 hours. For laboratory research use only.
