SS-31 (MTP-131)
Synthetic cardiolipin-targeted mitochondrial tetrapeptide (D-Arg-Dmt-Lys-Phe-NH2). Also known as Elamipretide, MTP-131, and Bendavia. Active pharmaceutical ingredient in FORZINITY, which received FDA accelerated approval on September 19, 2025, specifically to improve muscle strength in adult and pediatric patients with Barth syndrome weighing at least 30 kg. FDA approval applies solely to the prescription drug product FORZINITY and does not extend to unregulated research-grade SS-31 vials, compounded formulations, or unapproved anti-aging and athletic uses.
60-Second Scientific Briefing
FORZINITY (elamipretide / SS-31) received FDA accelerated approval on September 19, 2025, specifically to improve muscle strength in adult and pediatric patients with Barth syndrome weighing at least 30 kg. It selectively targets cardiolipin on the inner mitochondrial membrane. This FDA approval applies exclusively to FORZINITY for Barth syndrome and does NOT extend to unapproved SS-31 research vials, compounding, anti-aging regimens, or athletic performance use.
What is SS-31?
Pharmacological Classification & Molecular IdentitySynthetic cardiolipin-binding tetrapeptide designed to readily penetrate cell membranes and concentrate on the inner mitochondrial membrane; active pharmaceutical ingredient in FDA-approved FORZINITY (elamipretide).
Verified Chemical & Regulatory Registry Identifiers
Mechanism of Action & Receptor Targets
Biological Pathway and Target BindingBiological pathway and target receptor binding mechanism.
Receptor Selectivity: Selectively associates with cardiolipin on the inner mitochondrial membrane, preventing cytochrome c detachment, stabilizing cristae architecture, optimizing electron transport chain complexes, and restoring ATP production.
Regulatory & FDA Approval Status
Legal and Regulatory ClassificationsFORZINITY (elamipretide) received FDA accelerated approval on September 19, 2025, specifically indicated to improve muscle strength in adult and pediatric patients with Barth syndrome weighing at least 30 kg. FDA approval applies exclusively to the pharmaceutical drug product FORZINITY and does NOT make arbitrary SS-31 research vials, compounding, anti-aging regimens, or athletic performance use FDA-approved.
FORZINITY (elamipretide) received FDA accelerated approval on September 19, 2025, specifically indicated to improve muscle strength in adult and pediatric patients with Barth syndrome weighing at least 30 kg. This regulatory approval applies strictly to the prescription product FORZINITY for this specific orphan indication. It does NOT make arbitrary research-grade SS-31 vials, compounded formulations, anti-aging regimens, or athletic performance use FDA-approved or authorized.
Human Evidence & Clinical Trials
Clinical Study Readouts and Evidence SynthesesEvaluated in clinical trials including the double-blind, placebo-controlled TAZPOWER study and open-label extension in patients with Barth syndrome, demonstrating significant improvement in muscle strength (knee extensor and grip strength) leading to FDA accelerated approval for patients weighing >=30 kg.
Clinical Evidence
Evaluated in clinical trials including the double-blind, placebo-controlled TAZPOWER study and open-label extension in patients with Barth syndrome, demonstrating significant improvement in muscle strength (knee extensor and grip strength) leading to FDA accelerated approval for patients weighing >=30 kg.
Safety Profile & Clinical Limitations
Documented Adverse Events and Known UncertaintiesIn FDA labeling for FORZINITY and clinical trials, the most frequent adverse reactions (>=10%) are injection site reactions (erythema, pain, pruritus, bruising, swelling, induration), headache, and dizziness.
Continued accelerated approval for Barth syndrome is contingent upon verification of clinical benefit in confirmatory studies. Safety and efficacy remain completely unestablished for anti-aging, longevity, or exercise performance in individuals without Barth syndrome.
Dose Approval Status
Commercial Dosing Status and Policy DirectivesFORZINITY has an FDA-approved labeled dosage of 40 mg administered by subcutaneous injection once daily for adult and pediatric patients with Barth syndrome weighing at least 30 kg under healthcare provider guidance. Unregulated research-grade SS-31 vials have no approved dosing regimen or validated safety instructions.
Under Egypt Peptides medical governance policies, no personal dosages, titration intervals, cycles, stacking recommendations, or self-injection instructions may be provided for unapproved investigational compounds. Clinical study protocols represent controlled experimental research parameters exclusively.
What is Known vs. What is Unknown
Evidence Comparison and Clinical Evidence Boundaries✓ Confirmed Scientific Evidence
- Tetrapeptide sequence: D-Arg-Dmt-Lys-Phe-NH2 (Elamipretide / SS-31).
- FORZINITY (elamipretide) is FDA-approved under accelerated approval (Sept 19, 2025) to improve muscle strength in Barth syndrome patients weighing at least 30 kg.
- Selectively targets and stabilizes cardiolipin on the inner mitochondrial membrane to optimize electron transport chain efficiency.
- FDA approval applies exclusively to the approved prescription drug product FORZINITY; arbitrary research vials and anti-aging uses remain strictly unapproved.
? Unknown / Under Ongoing Investigation
- Confirmation of long-term clinical endpoints in Barth syndrome under ongoing confirmatory trials.
- Safety, efficacy, and regulatory authorization for non-Barth-syndrome uses, including anti-aging, longevity, and sports enhancement.
- Purity and sterility assurance of unregulated grey-market research peptide vials.
Verified Questions & Answers
10 Verified scientific answers with permanent anchor keysElamipretide (SS-31 / MTP-131) is a synthetic cardiolipin-targeting tetrapeptide (D-Arg-Dmt-Lys-Phe-NH2) and the active ingredient in FORZINITY, which received FDA accelerated approval for Barth syndrome. Unregulated research peptide vials sold online are distinct from the approved prescription drug.
Egypt Peptides classifies peptides strictly by validated molecular architecture and verifiable pharmacological mechanisms. Elamipretide is chemically defined as D-Arg-2,6-dimethyl-L-Tyr-Lys-L-Phe-NH2, selectively targeting mitochondrial cardiolipin.
- Elamipretide: The first cardiolipin-directed mitochondrial therapeutic for Barth syndrome approved under accelerated approval (Drug Discoveries & Therapeutics, 2026-01-07)
SS-31 exerts biological activity via Reversibly binds to cardiolipin, stabilizing mitochondrial membrane cristae architecture, preventing cytochrome c peroxidase transition, and optimizing ATP synthesis..
Receptor binding affinity and selectivity dictate the physiological response observed in laboratory and clinical trials.
- Elamipretide: The first cardiolipin-directed mitochondrial therapeutic for Barth syndrome approved under accelerated approval (Drug Discoveries & Therapeutics, 2026-01-07)
Yes, for a specific indication only. FORZINITY (elamipretide) received FDA accelerated approval on September 19, 2025, to improve muscle strength in adult and pediatric patients with Barth syndrome weighing at least 30 kg. FDA approval applies strictly to the prescription product FORZINITY; arbitrary research-grade SS-31 vials, compounded products, anti-aging uses, and exercise-performance applications remain unapproved.
The U.S. FDA granted accelerated approval to FORZINITY (elamipretide injection) based on clinical trial evidence demonstrating improvement in muscle strength in patients with Barth syndrome, an ultra-rare genetic mitochondrial disorder. Continued approval is contingent upon verification of clinical benefit in confirmatory trials. Crucially, this regulatory milestone does not make grey-market peptide vials labeled as SS-31, compounded peptide formulations, or off-label longevity interventions FDA-approved or legal for marketing.
- FDA Grants Accelerated Approval to FORZINITY (elamipretide) for Barth Syndrome (U.S. Food and Drug Administration, 2025-09-19)
- Drug Trials Snapshot: FORZINITY (elamipretide) (U.S. Food and Drug Administration, 2025-09-19)
- FDA Drugs@FDA Database: FORZINITY (Elamipretide Injection) Approval History and Prescribing Information (U.S. Food and Drug Administration, 2025-09-19)
- FDA Bulk Drug Substances Used in Compounding Under Section 503A of the FD&C Act (Category 2 Safety Evaluation) (U.S. Food and Drug Administration, 2023-09-29)
- Elamipretide: The first cardiolipin-directed mitochondrial therapeutic for Barth syndrome approved under accelerated approval (Drug Discoveries & Therapeutics, 2026-01-07)
Clinical evaluation status: Evaluated in clinical trials including the double-blind, placebo-controlled TAZPOWER trial and open-label extension in patients with Barth syndrome, supporting FDA accelerated approval for muscle strength improvement in patients >=30 kg.
Clinical trial readouts establish demonstrated therapeutic outcomes for the labeled indication, distinct from exploratory preclinical animal data.
- Elamipretide: The first cardiolipin-directed mitochondrial therapeutic for Barth syndrome approved under accelerated approval (Drug Discoveries & Therapeutics, 2026-01-07)
Reported safety profile: In FDA labeling for FORZINITY and clinical trials, the most frequent adverse reactions (>=10%) are injection site reactions (erythema, pain, pruritus, bruising, swelling), headache, and dizziness.
Adverse reaction monitoring and contraindications are critical parameters in pharmacological risk-benefit evaluation.
- Elamipretide: The first cardiolipin-directed mitochondrial therapeutic for Barth syndrome approved under accelerated approval (Drug Discoveries & Therapeutics, 2026-01-07)
Key scientific uncertainties: Long-term confirmatory clinical outcomes in Barth syndrome are still undergoing regulatory post-marketing trials. Safety and efficacy remain unproven for anti-aging, longevity, or athletic enhancement in healthy individuals.
Egypt Peptides enforces strict transparency regarding scientific limitations and gaps in longitudinal clinical data.
- FDA Bulk Drug Substances Used in Compounding Under Section 503A of the FD&C Act (Category 2 Safety Evaluation) (U.S. Food and Drug Administration, 2023-09-29)
FORZINITY has an FDA-approved labeled dosage of 40 mg administered subcutaneously once daily for adult and pediatric patients with Barth syndrome weighing at least 30 kg under medical supervision. Unregulated research SS-31 vials have no approved dosing regimen or validated safety guidelines.
Under the FDA-approved prescribing information for FORZINITY, the recommended dosage is 40 mg injected subcutaneously once daily under the guidance of a qualified healthcare provider for the labeled Barth syndrome indication. This labeled regimen must not be construed as individual medical advice or extrapolated to unauthorized research chemicals or healthy individuals.
- Elamipretide: The first cardiolipin-directed mitochondrial therapeutic for Barth syndrome approved under accelerated approval (Drug Discoveries & Therapeutics, 2026-01-07)
Official FDA labeling for FORZINITY requires refrigeration at 2°C to 8°C (36°F to 46°F) in the original carton to protect from light; do not freeze. These labeled storage instructions belong specifically to FORZINITY and cannot be generalized to unregulated research vials.
According to the FDA package insert, FORZINITY single-dose vials must be stored refrigerated between 2°C and 8°C (36°F to 46°F) and kept in the original carton to shield from light until administration. Vials should not be frozen or shaken vigorously. Unregulated grey-market research peptide vials lack pharmaceutical quality controls, certified excipients, and verified shelf-life stability.
- Elamipretide: The first cardiolipin-directed mitochondrial therapeutic for Barth syndrome approved under accelerated approval (Drug Discoveries & Therapeutics, 2026-01-07)
Yes. Unapproved pharmacological substances are strictly prohibited at all times in competitive sports under WADA Category S0 (Non-approved substances) or Category S2.
Athletes subject to drug testing face strict liability and multi-year competition bans upon detection of prohibited peptides or their metabolites.
- FDA Grants Accelerated Approval to FORZINITY (elamipretide) for Barth Syndrome (U.S. Food and Drug Administration, 2025-09-19)
- Drug Trials Snapshot: FORZINITY (elamipretide) (U.S. Food and Drug Administration, 2025-09-19)
- FDA Drugs@FDA Database: FORZINITY (Elamipretide Injection) Approval History and Prescribing Information (U.S. Food and Drug Administration, 2025-09-19)
- FDA Bulk Drug Substances Used in Compounding Under Section 503A of the FD&C Act (Category 2 Safety Evaluation) (U.S. Food and Drug Administration, 2023-09-29)
- Elamipretide: The first cardiolipin-directed mitochondrial therapeutic for Barth syndrome approved under accelerated approval (Drug Discoveries & Therapeutics, 2026-01-07)
Egypt Peptides provides peer-reviewed scientific reference monographs for research documentation. We strictly prohibit individual medical consultations, reconstitution guides, stacking recipes, or off-label use instructions.
All scientific claims must link to verified authoritative sources (FDA, PubMed, ClinicalTrials.gov) with zero tolerance for ungrounded marketing claims.
- Elamipretide: The first cardiolipin-directed mitochondrial therapeutic for Barth syndrome approved under accelerated approval (Drug Discoveries & Therapeutics, 2026-01-07)
Authoritative Sources & Literature Registry
Regulatory dossiers, clinical trial registries, and peer-reviewed studiesFDA Grants Accelerated Approval to FORZINITY (elamipretide) for Barth Syndrome ↗
https://www.fda.gov/drugs/news-events-human-drugs/fda-approves-elamipretide-barth-syndrome
Drug Trials Snapshot: FORZINITY (elamipretide) ↗
https://www.fda.gov/drugs/drug-approvals-and-databases/drug-trials-snapshots-forzinity
FDA Drugs@FDA Database: FORZINITY (Elamipretide Injection) Approval History and Prescribing Information ↗
https://www.accessdata.fda.gov/scripts/cder/daf/index.cfm?event=overview.process&ApplNo=215989
FDA Bulk Drug Substances Used in Compounding Under Section 503A of the FD&C Act (Category 2 Safety Evaluation) ↗
https://www.fda.gov/drugs/human-drug-compounding/bulk-drug-substances-used-compounding-under-section-503a-fdc-act
Elamipretide: The first cardiolipin-directed mitochondrial therapeutic for Barth syndrome approved under accelerated approval ↗
https://doi.org/10.5582/ddt.2025.01111