Description
SS-31 is a synthetic tetrapeptide, a chain of four amino acids, with the sequence D-Arg-Dmt-Lys-Phe-NH2. The peptide belongs to a class of mitochondria-targeted compounds designed with an alternating aromatic-cationic motif (positive charge, aromatic ring, positive charge, aromatic ring) that gives it membrane-permeable characteristics. It carries a net positive charge at physiological pH from its arginine and lysine residues, and has a structural affinity for cardiolipin, a phospholipid found almost exclusively in the inner mitochondrial membrane.
SS-31 has an unusually well-documented clinical development path for a research peptide. Stealth BioTherapeutics advanced it into human trials under the name elamipretide, studying it for Barth syndrome (a rare genetic mitochondrial disorder), primary mitochondrial myopathy, and dry AMD, with completed Phase 2 and Phase 3 studies in several of these indications. This gives SS-31 a deeper base of published human pharmacology and safety data than most compounds sold as research peptides, centered on its proposed mechanism of stabilizing cardiolipin and improving mitochondrial bioenergetic efficiency.
The molecular formula is C32H49N9O5, molecular weight approximately 639.8 g/mol, CAS 736992-21-5. SS-31 is supplied as a white to off-white lyophilized powder that is soluble in water. This product is strictly for research purposes only and is not approved for human or animal use.
PubChem Reference: View compound profile on NIH PubChem
Key Characteristics
MOLECULAR PROFILE
Formula: C₃₂H₄₉N₉O₅
Weight: 639.8 g/mol
CAS: 736992-21-5
Sequence: D-Arg-Dmt-Lys-Phe-NH₂
PHYSICAL PROPERTIES
Form: White to off-white lyophilized powder
Solubility: Water-soluble
Storage: Keep refrigerated 36‑46 °F (2‑8 °C)
Stability: Stable when properly stored
SS-31 in Published Research
Because elamipretide has been through registered clinical trials, published research on SS-31 covers more than typical preclinical peptide literature. Studies have examined its effects on mitochondrial membrane potential, ATP synthesis efficiency, and oxidative stress markers in models of heart failure and ischemia-reperfusion injury, alongside the human trial data from its Barth syndrome and mitochondrial myopathy programs. Trial results have been mixed across indications, some showing functional improvement, others not meeting primary endpoints, which is worth noting as balanced research context rather than treating it as a universally validated compound.
Frequently Asked Questions :
What is SS-31 studied for?
Mitochondrial dysfunction, heart failure, ischemia-reperfusion injury, and age-related mitochondrial decline, via its cardiolipin-stabilizing mechanism.
Has it been in human clinical trials?
Yes, as elamipretide, through Phase 2/3 trials for Barth syndrome, primary mitochondrial myopathy, and dry AMD, more advanced than most research peptides.
What do the trials show?
Mixed results across indications; some endpoints showed improvement, others did not, reflecting real trial outcomes rather than uniform success.
How should it be reconstituted and stored?
Bacteriostatic water, refrigerate 2–8°C.
Where can I buy SS-31 for research?
10mg and 50mg kits, HPLC/MS verified.
Jason Park –
First time ordering SS-31 from this vendor. CAS number (736992-21-5) matched perfectly. Vacuum seal was intact, and shipping was faster than expected. Will definitely be a repeat customer
Dr. Michelle Reynolds –
Excellent quality SS-31. I’ve tested peptides from several suppliers, and PeptidesVital ranks among the best. The product is clean, soluble, and consistent. Free shipping over $200 is a great perk
Dr. Anita Desai –
Very happy with my purchase. SS-31 reconstituted crystal clear and showed no signs of peptide aggregation. The price is fair for the quality offered. Will recommend to colleagues
Dr. Elena Vasquez –
SS-31 arrived promptly and in excellent condition. The lyophilized powder reconstituted beautifully with no residue. Our mitochondrial research depends on high-purity peptides, and this batch delivered. Highly recommend PeptidesVital
Dr. Sophia Chen –
International shipping was smooth and well-tracked. SS-31 arrived in perfect shape with clear labeling. The peptide performed exactly as expected in our assays. PeptidesVital is now my go-to supplier
Christopher Lane –
PeptidesVital consistently delivers top-notch products. SS-31 arrived well-packaged with documentation. Our lab has seen reproducible results across multiple trials. Definitely ordering in bulk next time
Brian Foster –
Reliable vendor with great customer support. Highly satisfied
Kevin Anderson –
Ordered SS-31 for a new research protocol. Very impressed with the purity and packaging. Customer service answered my questions about storage quickly. Five stars will order again