Made in USA · ≥99% HPLC
Mitochondrial Peptide
View full COA report
SS-31 (Elamipretide) 10mg
ElamipretideMTP-131D-Arg-Dmt-Lys-Phe-NH₂
A mitochondria-targeting tetrapeptide (D-Arg-Dmt-Lys-Phe-NH₂) that binds cardiolipin in the inner mitochondrial membrane, supplied as 10 mg of sterile lyophilized powder for in-vitro study.
$49.95
17 in stock
For laboratory and research use only. Not for human consumption.
This product is not a drug, food or cosmetic. It is sold exclusively to qualified researchers and licensed laboratories.
17 in stock
Tested by Freedom Diagnostics TestingHPLC purity + LC-MS identityLot-matched COA on-site
Arrives in 3–5 days
Free shipment protection
Secure encrypted payment
Verified COA
Batch-tested & posted · Freedom Diagnostics
Purity (HPLC-UV)99.924%
Identity (LC-MS)Confirmed
Net content12.34 mg
ReportedMar 22, 2026
US-synthesizedMade & lab-released in the United States
Independent COAThird-party Certificate of Analysis per lot
HPLC + LC-MSPurity by HPLC, identity by mass spectrometry
Same-day dispatchOrders before 2 PM CT ship the same business day
What is SS-31?
SS-31 (also known as elamipretide and MTP-131) is a synthetic mitochondria-targeting tetrapeptide (D-Arg-Dmt-Lys-Phe-NH2) that concentrates selectively in the inner mitochondrial membrane through cardiolipin binding. Its alternating aromatic-cationic structure and 3+ net charge drive accumulation without any receptor or transporter, where it stabilizes cardiolipin-rich cristae and supports the scaffold that organizes Complex I–IV respiratory supercomplexes. The non-canonical 2′,6′-dimethyltyrosine (Dmt) residue at position 2 acts as a radical sink that scavenges reactive oxygen species at the membrane source.
Research areas where laboratories buy SS-31 for in vitro work include cardiolipin-binding studies in isolated mitochondria and inner-membrane vesicles, ROS-scavenging assays leveraging the dimethyltyrosine radical sink, electron-transport-chain efficiency in permeabilized cardiac and skeletal-muscle fibers, kidney ischemia-reperfusion models in rodents, tafazzin (TAZ) knockdown cell models of cardiolipin remodeling, and retinal ganglion cell cultures. It is an investigational compound and is not approved by the FDA for any indication.
Every lot, independently verified
Independently third-party tested and matched to the lot ID printed on your vial. Values below are from the latest released lot.
99.92%
HPLC-UV Purity
Passed full QC panel
Independent third-party lab (Freedom Diagnostics Testing)
View COA (PDF)
Latest batch · tested 22 Mar 2026 · Freedom Diagnostics (USA)
Lot details
ProductSS-31 10 mg
LotClear Cap / Blue Crimp
AppearanceWhite lyophilized powder
Accession #2603200300
Reported22 Mar 2026
Full QC panel · third-party lab7 assays
Purity (HPLC-UV)99.924% ✓
Identity (LC-MS)SS-31 · Dmt confirmed ✓
HPLC conformity (2×)Confirmed ✓
Net content12.34 mg ✓
Heavy metals (ICP-MS)Not Detected ✓
SterilityNo Growth ✓
Endotoxin (USP <85>)Within limits ✓
Every lot is released against Koi's full QC panel — HPLC purity, LC-MS identity (verifying the non-canonical 2′,6′-dimethyltyrosine residue), net content, heavy metals, sterility, and endotoxin — by an independent third-party laboratory (Freedom Diagnostics Testing). Values shown are from the latest released lot (Clear Cap / Blue Crimp, reported 22 Mar 2026) and vary batch to batch; the lot-specific certificate is published in our public COA library and matched to the lot ID printed on the vial.
Browse full COA library →
Compound information
Chemical & structural reference data — specifications, molecular profile and handling.
Product Specifications
CompoundSS-31 (elamipretide; mitochondria-targeting tetrapeptide)
Vial size10 mg
Purity≥99% by HPLC
Identity confirmationMass spectrometry (Dmt confirmed)
FormWhite lyophilized powder
Appearance in solutionClear, colorless solution
ManufacturingSynthesized and lyophilized in the United States
Quality testingIndependent third-party laboratory release (Freedom Diagnostics Testing)
Molecular Profile
SequenceH-D-Arg-Dmt-Lys-Phe-NH2
Molecular formulaC32H49N9O5 (free base)
Molecular weight639.78 g/mol
CAS number736992-21-5
PubChem CID11764719
Net charge3+ at physiological pH
Other namesElamipretide · MTP-131
Storage & Handling
AppearanceWhite lyophilized powder
SolubilitySterile water (3+ charge)
Storage · powder−20 °C, desiccated, dark (−80 °C long-term)
In solution2–8 °C; avoid oxidizers
SS-31 Mechanism of Action
- Concentrates selectively in the inner mitochondrial membrane through cardiolipin binding, driven by the 3+ net charge and alternating aromatic-cationic structure — not through any receptor or transporter.
- Stabilizes cardiolipin-rich cristae curvature, supporting the scaffold that organizes Complex I–IV respiratory supercomplexes.
- Scavenges reactive oxygen species via the 2′,6′-dimethyltyrosine (Dmt) residue at position 2, a radical sink that quenches oxidative damage at the membrane source.
- Resists protease degradation through the D-stereochemistry of the position-1 arginine, extending functional half-life relative to all-L peptides.
- Improves electron-transport-chain coupling and ATP-synthesis efficiency in permeabilized cardiac and skeletal-muscle fibers, measurable by high-resolution respirometry.
- Carries no cell-surface receptor activity, placing it in a small class of mitochondria-localizing research compounds.
SS-31 Research Applications
- Cardiolipin binding studies in isolated mitochondria and inner-membrane vesicle preparations.
- ROS-scavenging assays leveraging the dimethyltyrosine radical-sink mechanism.
- Electron-transport-chain efficiency in permeabilized cardiac and skeletal-muscle fibers — supercomplex assembly and Complex I–IV coupling.
- Kidney ischemia-reperfusion models in rodents, measuring mitochondrial function during reperfusion.
- Tafazzin (TAZ) knockdown cell models of cardiolipin remodeling.
- Mitochondrial function in retinal ganglion cell cultures.
Why Buy SS-31 from Koi Peptides?
- Every batch of Koi SS-31 is synthesized and lyophilized in the United States, then released against independent third-party laboratory (Freedom Diagnostics Testing) testing.
- Each lot is tested by HPLC for purity, LC-MS for identity confirmation including the non-canonical dimethyltyrosine residue, and screened for endotoxin before release.
- The lot ID is printed on every vial and ties back to a public COA library, so researchers can verify documentation before they buy and after the vial arrives.
- Orders placed before 2 PM CT ship the same business day, and shipping is free on orders over $200.
References
The laboratory and preclinical research behind SS-31 (elamipretide) — cited for scientific context.
J. Biological Chemistry
Cell-permeable peptide antioxidants targeted to inner mitochondrial membrane
Antioxid. Redox Signal.
Mitochondria-targeted cytoprotective peptides for ischemia-reperfusion injury
J. Am. Soc. Nephrology
SS-31 re-energizes ischemic mitochondria by interacting with cardiolipin
View all references +
- Zhao, K., et al. (2004). Cell-permeable peptide antioxidants targeted to inner mitochondrial membrane. Journal of Biological Chemistry, 279(33), 34682–34690. doi.org/10.1074/jbc.M402999200
- Szeto, H. H. (2008). Mitochondria-targeted cytoprotective peptides for ischemia-reperfusion injury. Antioxidants & Redox Signaling, 10(3), 601–619. doi.org/10.1089/ars.2007.1892
- Birk, A. V., et al. (2013). SS-31 re-energizes ischemic mitochondria by interacting with cardiolipin. Journal of the American Society of Nephrology, 24(8), 1250–1261. doi.org/10.1681/ASN.2012121216
- Szeto, H. H., et al. (2011). Mitochondria-targeted peptide accelerates ATP recovery and reduces ischemic kidney injury. Journal of the American Society of Nephrology, 22(6), 1041–1052. doi.org/10.1681/ASN.2010080808
- Mitchell, W., et al. (2020). SS-31 binds lipid bilayers and modulates surface electrostatics. Journal of Biological Chemistry, 295(21), 7452–7469. doi.org/10.1074/jbc.RA119.012287
- Allen, M. E., et al. (2020). Elamipretide alters cardiolipin in cardiac mitochondria. Communications Biology, 3, 389. doi.org/10.1038/s42003-020-1101-3
Regulatory Status
Regulatory status — provided for research context.
Regulatory Status
Regulatory status — provided for research context.
FDA Status
SS-31 (elamipretide, MTP-131) is an investigational compound and is not approved by the FDA for any indication. The research-grade material supplied by Koi Peptides is synthesized for laboratory research only; it is not formulated, packaged or labeled as a drug, food or cosmetic.
Disclaimer
For laboratory and research use only. Not for human consumption. This product is not a drug, food or cosmetic. It is sold exclusively to qualified researchers and licensed laboratories. These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure or prevent any disease.
Frequently Asked Questions About SS-31
What is SS-31 used for in research?+
Mitochondrial pharmacology labs use SS-31 across cardiolipin-binding studies in inner-membrane vesicles, ROS-scavenging assays via the dimethyltyrosine sink, and ETC efficiency in permeabilized cardiac and skeletal fibers. Model work covers rodent kidney ischemia-reperfusion, TAZ knockdown cardiolipin models, and retinal ganglion cell cultures.
What purity is Koi's SS-31?+
Lots are released at ≥99% by HPLC (latest 99.92%) with LC-MS-confirmed identity — including the non-canonical 2′,6′-dimethyltyrosine at position 2 and the D-arginine at position 1. The third-party panel covers HPLC purity, LC-MS identity, net content, heavy metals, sterility, and endotoxin, with a COA published against the lot number printed on the vial.
How do I prepare an SS-31 solution?+
It dissolves readily in sterile water given its 3+ charge — no acidic buffer or cosolvent needed. Add diluent down the vial wall, let the cake dissolve without vortexing, and prepare 1–5 mg/mL stocks. Filter through a 0.22 µm low-protein-binding filter for sterile cell-culture work and avoid strong oxidizers.
What is the CAS number for SS-31?+
CAS 736992-21-5 identifies the free base and the PubChem CID is 11764719. It also appears as MTP-131 and elamipretide (INN), with a molecular weight of 639.78 g/mol.
Is SS-31 for human use?+
No. SS-31 is for laboratory and research use only and is not for human consumption. It is sold exclusively to qualified researchers and licensed laboratories.
Does SS-31 come with a Certificate of Analysis?+
Yes. The lot-specific Certificate of Analysis is published in our public COA library and matched to the lot ID printed on the vial. It documents HPLC purity, LC-MS identity, net content, heavy metals, sterility, endotoxin, and the salt form (acetate or trifluoroacetate) — important for accurate molar concentration from peptide weight.
How should SS-31 be stored?+
Store the lyophilized powder at −20 °C, desiccated and protected from light; for long-term storage −80 °C is preferred. Once dissolved, store at 2 to 8 °C and avoid strong oxidizers. Avoid repeated freeze-thaw cycles.
Is SS-31 FDA-approved?+
No. SS-31 (elamipretide) is an investigational compound and is not approved by the FDA for any indication. The material supplied by Koi Peptides is for laboratory and research use only.
Stock your lab with Koi
Research-grade peptides — made in the USA, third-party tested, with public lot-matched COAs. Shop the catalog, or contact our team with questions.
