SS-20
SS-20 is a mitochondria-targeted tetrapeptide in the Mitochondrial Peptide class. Like other Szeto-Schiller peptides, SS-20 concentrates in the inner mitochondrial membrane in a membrane-potential-independent manner. Unlike elamipretide it does not carry the dimethyltyrosine residue responsible for cardiolipin binding and radical scavenging, and reported effects on mitochondrial morphology and bioenergetics appear to proceed through a different mechanism.
For research use only.
Key Facts
- CAS
- 736992-19-1
- Molecular Weight (MW)
- 595.7 g/mol
- Half-life
- —
- FDA status
- Not Approved
- Administration Route
- subcutaneous
- Frequency
- —
- Last updated
- Sep 26, 2026
- Reviewed
- Aug 30, 2026
Research summary
Mitochondria-targeted tetrapeptide from the same Szeto-Schiller series as elamipretide, distinguished by lacking the dimethyltyrosine residue that gives elamipretide its cardiolipin affinity. Not FDA-approved; preclinical only.
Peptide Library's SS-20 profile summarises 3 cited studies listed in the Science section, the compound's regulatory status, and research-protocol parameters reported for it. It is a research reference, not medical advice.
Protocol
- Dosage Range
- —
- Frequency
- —
- Cycle
- —
- Administration Route
- subcutaneous
- Reconstitution Guide
- —
Not yet checked against primary sources
These figures are compiled from earlier reference material. They have not been verified against FDA labelling, registered trials or published literature, no citation is attached to them, and none of them is a recommended dose. SS-20 is queued for dosage evidence review.
Compare reported doses across the whole librarySequence & molecular data
| Molecular formula | C30H45N9O4 |
|---|---|
| Molecular weight | 595.7 g/mol |
| CAS number | 736992-19-1 |
| PubChem CID | 10008657 |
| FDA UNII | U260G1W6DY |
Identifiers link to the public PubChem, FDA Substance Registration (UNII), ChEMBL and DrugBank records for the same entity.
Science
Mechanism of Action
Like other Szeto-Schiller peptides, SS-20 concentrates in the inner mitochondrial membrane in a membrane-potential-independent manner. Unlike elamipretide it does not carry the dimethyltyrosine residue responsible for cardiolipin binding and radical scavenging, and reported effects on mitochondrial morphology and bioenergetics appear to proceed through a different mechanism. It is used mainly as a comparator that separates cardiolipin-dependent from cardiolipin-independent effects.
Studies
- A mitochondria-targeted idebenone derivative W1a mitigates cerebral ischemia-reperfusion injury by preserving mitochondrial integrity and suppressing neuroinflammation
- Quantifying tetrapeptide SS-20 in rat plasma using hydrophilic interaction liquid chromatography coupled with electrospray ionization tandem mass spectrometry
- Improved mitochondrial targeting effect of HPMA copolymer by SS20 peptide mediation and nonendocytosis pathway
Regulatory & research status
SS-20 is not an FDA-approved product. It is sold for laboratory research and has no approved medical use.
| FDA status | Not Approved |
|---|---|
| Research status | Research-only compound; no approval pathway listed |
| Availability | Research-Only |
| WADA (sport) | Unknown / Not Listed |
| Library classification | Research-Only |
Benefits
—
SS-20 side effects
No side effects listed yet for this entry.
Storage & stability
Lyophilized (freeze-dried) peptide powder is far more stable than the reconstituted solution. Keep sealed vials cold, dry and away from light; long-term storage is typically frozen, with short-term refrigeration for vials in use.
Once reconstituted in bacteriostatic water, keep the solution refrigerated, avoid repeated freeze–thaw cycles and agitation, and label the vial with the reconstitution date and concentration. Discard any solution that turns cloudy or shows particulates.
Degradation rates differ by sequence: peptides containing methionine, cysteine, asparagine or glutamine are more prone to oxidation and deamidation, so shelf life after reconstitution is compound-specific rather than universal.
Read the full guide: how to store peptides before and after reconstitution →
Source: Manning MC, Chou DK, Murphy BM, Payne RW, Katayama DS. Stability of protein pharmaceuticals: an update. Pharm Res. 2010;27(4):544–575. (PMID 20143256). General guidance for research handling; not product-specific instructions.
SS-20: frequently asked questions
What is SS-20?
Mitochondria-targeted tetrapeptide from the same Szeto-Schiller series as elamipretide, distinguished by lacking the dimethyltyrosine residue that gives elamipretide its cardiolipin affinity. Not FDA-approved; preclinical only.
How does SS-20 work?
Like other Szeto-Schiller peptides, SS-20 concentrates in the inner mitochondrial membrane in a membrane-potential-independent manner. Unlike elamipretide it does not carry the dimethyltyrosine residue responsible for cardiolipin binding and radical scavenging, and reported effects on mitochondrial morphology and bioenergetics appear to proceed through a different mechanism.
Is SS-20 FDA approved?
No. SS-20 is not approved by the FDA for any indication and is categorised as research-only. It has not been reviewed for safety or efficacy as a medicine, and published research should be read as investigation rather than established use.
What peptides are similar to SS-20?
Compounds most often compared with SS-20 include MOTS-C, Humanin, Humanin-G (HNG) and Elamipretide (SS-31). They are grouped by shared mechanism or research area rather than by equivalence, and their regulatory status and evidence base differ.
References
- A mitochondria-targeted idebenone derivative W1a mitigates cerebral ischemia-reperfusion injury by preserving mitochondrial integrity and suppressing neuroinflammation — Bioorg Chem, 2026External reference
- Quantifying tetrapeptide SS-20 in rat plasma using hydrophilic interaction liquid chromatography coupled with electrospray ionization tandem mass spectrometry — J Chromatogr B Analyt Technol Biomed Life Sci, 2011External reference
- Improved mitochondrial targeting effect of HPMA copolymer by SS20 peptide mediation and nonendocytosis pathway — J Pept Sci, 2019External reference
Related research, comparisons & guides
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Compiled by Peptide Library Editorial · Reviewed Aug 30, 2026 · Updated Sep 26, 2026 · Version 3
This SS-20 profile is compiled from published literature (3 cited studies linked above), public regulatory records and chemical registries. It describes what research reports; it is not medical advice, and nothing here is a dosing recommendation for humans. Peptide Library does not sell peptides. Editorial policy · How profiles are compiled · Report an error
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