Elamipretide (SS-31)
Also known as: MTP-131, Bendavia, Forzinity, Szeto-Schiller peptide
Elamipretide (SS-31), also called MTP-131 or Bendavia, is an FDA-approved mitochondria-targeted tetrapeptide in the Mitochondrial Peptide class. Elamipretide is a cell-permeable aromatic-cationic tetrapeptide that concentrates in the inner mitochondrial membrane in a manner not dependent on membrane potential, so it accumulates even in depolarised, dysfunctional mitochondria.
For research use only.
Key Facts
- CAS
- 736992-21-5
- Molecular Weight (MW)
- 639.8 g/mol
- Half-life
- ~4–5 h (iv) in human studies
- FDA status
- Approved
- Evidence level
- FDA Approved
- Human dose established
- Yes
- Administration Route
- Subcutaneous
- Frequency
- Once daily, at the same time each day
- Last updated
- Sep 6, 2026
- Reviewed
- Aug 30, 2026
- Targets
- CardiolipinInner mitochondrial membrane
Vendor price snapshot
Each vendor counts once, at the median price per mg of its own listings; the typical range is the middle half of vendors. From public vendor listings collected between Nov 2025 and Sep 2026, so confirm the live price on the vendor site. Peptide Library does not sell peptides.
- Vendors listing this peptide
- 25
- Listed offers
- 30
- Median price per mg
- $5.20/mg
- Typical $4.50–$8.00/mg
Research summary
Mitochondria-targeted tetrapeptide. FDA granted accelerated approval in September 2025 to Forzinity (elamipretide) to improve muscle strength in Barth syndrome patients ≥30 kg. Confirmatory trial required.
Peptide Library's Elamipretide (SS-31) profile summarises 5 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.
Elamipretide (SS-31) dosage chart
Elamipretide, also sold as SS-31, has an FDA-approved human dosage: 40 mg subcutaneously once daily, approved as Forzinity to improve muscle strength in adult and paediatric patients with Barth syndrome weighing at least 30 kg. The approval is narrow, and the wider programme in mitochondrial myopathy, dry age-related macular degeneration and cardiac reperfusion injury did not lead to approval in those conditions.
| Human dosing established | Yes |
|---|---|
| Studied dose range | 40 mg once daily (20 mg in severe renal impairment) |
| Route | Subcutaneous |
| Frequency | Once daily, at the same time each day |
| Duration studied | Continuous |
| Titration | None. The approved dose is fixed; the only adjustment is a reduction for severe renal impairment. |
| Evidence level | FDA Approved |
| Last reviewed | 2026-09-05 |
Research-reported dosing
Doses as studied, one row per regimen. Different trials used different regimens; they are listed separately rather than averaged.
| Study / context | Population | Dose | Route | Frequency | Duration | Outcome studied | Source |
|---|---|---|---|---|---|---|---|
| FDA label — Forzinity, Barth syndromeFDA-approved label · FDA prescribing information | Adults and paediatric patients with Barth syndrome weighing at least 30 kg | 40 mg (20 mg if eGFR below 30 mL/min and not on dialysis) | Subcutaneous | Once daily | Continuous | Muscle strength | FORZINITY (elamipretide hydrochloride) injection — FDA prescribing information, DailyMed |
| NCT05162768 — phase 3, Barth syndromeClinical trial · Phase 3 trial, completed | Subjects with Barth syndrome (n=102) | Per trial protocol | Subcutaneous | Once daily | Per trial protocol | Efficacy and safety in Barth syndrome | NCT05162768 — Study to Evaluate Efficacy and Safety of Elamipretide in Subjects With Barth Syndrome |
| ReCLAIM-2 — phase 2, dry age-related macular degenerationClinical trial · Phase 2 trial with posted results | Patients with dry AMD and geographic atrophy (n=176) | Per trial protocol | Subcutaneous | Once daily | 48 weeks | Safety, efficacy and pharmacokinetics | NCT03891875 — ReCLAIM-2 Study to Evaluate Safety, Efficacy and Pharmacokinetics of Elamipretide |
| EMBRACE STEMI — phase 2, cardiac reperfusion injuryClinical trial · Phase 2 trial with posted results | Patients with ST-elevation myocardial infarction (n=300) | Per trial protocol (MTP-131 / Bendavia) | Intravenous | — | — | Reduction of reperfusion injury | NCT01572909 — Evaluation of Myocardial Effects of MTP-131 for Reducing Reperfusion Injury |
Where sources disagree
- The approved 40 mg daily dose is specific to Barth syndrome, a rare genetic cardiolipin disorder. Doses quoted elsewhere for general mitochondrial, longevity or performance purposes have no approved indication and no positive phase 3 trial behind them.
- SS-31, elamipretide, MTP-131 and Bendavia are the same molecule under different development names. Trials are indexed under all four, which makes the evidence base look larger or smaller than it is depending on the name searched.
- Research-grade SS-31 is typically sold in 10–50 mg vials with protocols in the low milligram range. The approved daily dose is 40 mg, substantially higher than most of those protocols, and was established under clinical monitoring in a rare-disease population.
- This library lists elamipretide and SS-31 as separate profiles for the same compound. The evidence below is identical; SS-31, MTP-131 and Bendavia are earlier development names for elamipretide.
Reconstitution
Common research vial sizes: 10 mg, 50 mg.
| Vial | Bacteriostatic water | Concentration | Per 0.01 mL |
|---|---|---|---|
| 10 mg | 2 mL | 5 mg/mL | 50 mcg per 0.01 mL |
| 50 mg | 2 mL | 25 mg/mL | 250 mcg per 0.01 mL |
These figures are arithmetic only — they convert a vial and a volume into a concentration. They are not a recommendation to take any dose.
Calculate reconstitution & dose →Handling & administration
- Reconstitution Guide
- Use approved Forzinity presentation per label
- Injection Sites
- AbdomenThigh
- Concentration Example
- Labeled 40 mg SC daily
- Timing Notes
- Prescription product; not a research-vial protocol
- Expected Onset
- Strength changes assessed over weeks to months in trials
Sequence & molecular data
| Amino acid sequence | D-Arg-Dmt-Lys-Phe-NH2 |
|---|---|
| Molecular formula | C32H49N9O5 |
| Molecular weight | 639.8 g/mol |
| CAS number | 736992-21-5 |
| Half-life | ~4–5 h (iv) in human studies |
| Appearance | Lyophilized powder for IV / SC infusion (investigational) |
| Formulation | Solution |
| PubChem CID | 11764719 |
| FDA UNII | 87GWG91S09 |
| ChEMBL | CHEMBL3833370 |
| DrugBank | DB11981 |
Identifiers link to the public PubChem, FDA Substance Registration (UNII), ChEMBL and DrugBank records for the same entity.
Science
Mechanism of Action
Elamipretide is a cell-permeable aromatic-cationic tetrapeptide that concentrates in the inner mitochondrial membrane in a manner not dependent on membrane potential, so it accumulates even in depolarised, dysfunctional mitochondria. It binds cardiolipin, the signature phospholipid of that membrane, which is required for the structural organisation of cristae and for the assembly and efficiency of the electron transport chain supercomplexes. By stabilising cardiolipin it improves cristae architecture and electron transfer efficiency and reduces electron leak, lowering reactive oxygen species production at source rather than scavenging radicals after formation. In Barth syndrome the underlying tafazzin defect impairs cardiolipin remodelling directly, which is the rationale for its use there.
Origin
Synthetic aromatic-cationic tetrapeptide (D-Arg-Dmt-Lys-Phe-NH2).
Targets
Studies
- Genotype-specific effects of elamipretide in patients with primary mitochondrial myopathy: a post hoc analysis of the MMPOWER-3 trial
- Efficacy and Safety of Elamipretide in Individuals With Primary Mitochondrial Myopathy: The MMPOWER-3 Randomized Clinical Trial
- Elamipretide: First Approval
- Elamipretide: A Review of Its Structure, Mechanism of Action, and Therapeutic Potential
- Elamipretide in the Management of Barth Syndrome: Current Evidence and a Case Report
Regulatory & research status
Elamipretide (SS-31) is an FDA-approved product for specific labelled indications. Approval does not extend to the research contexts described on this page, and approved products are prescription medicines.
| FDA status | Approved |
|---|---|
| Availability | Prescription-Only |
| WADA (sport) | Permitted |
| Library classification | FDA-Approved |
Benefits
Elamipretide (SS-31) side effects
The effects below are drawn from Elamipretide (SS-31)'s prescribing information, which lists the full adverse-reaction data.
Side Effects
- Injection-site reactions
- Eosinophilia reported in development
- Headache
Contraindications
- Hypersensitivity to elamipretide
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.
Elamipretide (SS-31): frequently asked questions
What is Elamipretide (SS-31)?
Mitochondria-targeted tetrapeptide. FDA granted accelerated approval in September 2025 to Forzinity (elamipretide) to improve muscle strength in Barth syndrome patients ≥30 kg. Confirmatory trial required. Elamipretide is a cell-permeable aromatic-cationic tetrapeptide that concentrates in the inner mitochondrial membrane in a manner not dependent on membrane potential, so it accumulates even in depolarised, dysfunctional mitochondria. It binds cardiolipin, the signature phospholipid of that membrane, which is required for the structural organisation of cristae and for the assembly and efficiency of the electron transport chain supercomplexes.
How does Elamipretide (SS-31) work?
Elamipretide is a cell-permeable aromatic-cationic tetrapeptide that concentrates in the inner mitochondrial membrane in a manner not dependent on membrane potential, so it accumulates even in depolarised, dysfunctional mitochondria. It binds cardiolipin, the signature phospholipid of that membrane, which is required for the structural organisation of cristae and for the assembly and efficiency of the electron transport chain supercomplexes.
Is Elamipretide (SS-31) FDA approved?
Yes. Elamipretide (SS-31) is approved by the FDA, and approved products are prescription medicines. Approval is always for specific indications studied in clinical trials, so an approved status does not mean the compound is approved for every use it is discussed for. Research-chemical material sold under the same name is not the approved product.
What is the half-life of Elamipretide (SS-31)?
Reported half-life for Elamipretide (SS-31) is ~4–5 h (iv) in human studies. Half-life describes how long the compound persists in circulation, not how long any effect lasts, and published figures vary with route of administration, formulation and the population studied.
What is the amino acid sequence of Elamipretide (SS-31)?
Elamipretide (SS-31) has the sequence D-Arg-Dmt-Lys-Phe-NH2, giving a chain of 5 amino acids. Its molecular formula is C32H49N9O5.
Is Elamipretide (SS-31) banned in sport?
Elamipretide (SS-31) is recorded here as permitted in sport. Anti-doping status is revised annually, so athletes subject to testing should confirm against the current WADA Prohibited List before use.
How long does Elamipretide (SS-31) take to show effects in research protocols?
The research protocol on this profile lists an expected onset of strength changes assessed over weeks to months in trials. This is a protocol note describing when studies and researchers report observing changes, not a measured clinical outcome, and it varies with the model, dose and endpoint studied.
Where is Elamipretide (SS-31) administered in research protocols?
Research protocols on this profile use subcutaneous administration, with recorded sites including abdomen, thigh. Site rotation and sterile technique are standard practice in the research literature; this describes protocol conditions and is not guidance for use.
References
- FDA accelerated approval — ForzinityExternal reference
- DailyMed — ForzinityExternal reference
- Genotype-specific effects of elamipretide in patients with primary mitochondrial myopathy: a post hoc analysis of the MMPOWER-3 trial — Orphanet J Rare Dis, 2024External reference
- Efficacy and Safety of Elamipretide in Individuals With Primary Mitochondrial Myopathy: The MMPOWER-3 Randomized Clinical Trial — Neurology, 2023External reference
- Elamipretide: First Approval — Drugs, 2026External reference
- Elamipretide: A Review of Its Structure, Mechanism of Action, and Therapeutic Potential — Int J Mol Sci, 2025External reference
- Elamipretide in the Management of Barth Syndrome: Current Evidence and a Case Report — Mol Genet Metab, 2025External reference
Related research, comparisons & guides
- SS-31 (Elamipretide): A Peptide That Targets the Mitochondrial Membrane
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- Peptide dosage chart: dose, route and frequencyCategory
- Peptide calculator with the Elamipretide (SS-31) preset
- How to store peptides before and after reconstitution
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Compiled by Peptide Library Editorial · Reviewed Aug 30, 2026 · Updated Sep 6, 2026 · Version 3
This Elamipretide (SS-31) profile is compiled from published literature (5 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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