The Peptide Field. SS-31: approval and evidence record.

Editorial review: 2026-08-30. Dataset version: 2026-09-11.1.

https://thepeptidefield.com/peptides/ss-31

Lookup: https://thepeptidefield.com/peptide-evidence-checker?peptide=ss-31#result

This is a dated editorial summary, not a live FDA check or independent medical review. It does not recommend treatment or verify a product in hand.

Status: Forzinity has FDA accelerated approval for a narrow Barth syndrome use

Exact product limits: FDA maps SS-31 to elamipretide, but the approval is for the specific Forzinity product and a narrow use. An online product labeled SS-31 or elamipretide is not automatically the same product as Forzinity.

Human outcomes: Moderate. FDA approval covers one rare disease and one muscle-strength measure. Results in other conditions have been mixed, including a negative phase 3 study.

Body effects in people: Strong. The FDA label describes elamipretide's four-amino-acid sequence and its binding to cardiolipin inside mitochondria.

What the evidence shows: FDA granted Forzinity accelerated approval for adults and children with Barth syndrome who weigh at least 30 kg. The main study included 12 males age 12 or older at one U.S. site. In the randomized part, Forzinity did not beat placebo for walking distance or fatigue. FDA relied on knee-muscle strength measured during a later open-label extension, when everyone knew they received Forzinity. FDA requires another randomized study to confirm a patient benefit. In a separate 24-week study, 218 people with primary mitochondrial myopathy did not have better walking distance or fatigue with elamipretide than with placebo.

What remains unknown: One small study in healthy older adults measured how well muscle mitochondria made energy. It did not establish more daily energy, less fatigue, longer life, or slower aging. Results in Barth syndrome do not transfer to healthy people or other diseases. FDA approval names the controlled Forzinity product. It does not show that an online SS-31 vial has the same formulation, quality controls, or evidence.

Safety limits: The Forzinity label warns about serious allergic reactions and injection-site reactions. Those warnings apply to the approved product and do not prove that another SS-31 product is the same. This guide gives no dosing, injection, sourcing, product-use, treatment, or performance advice.

Product record: Forzinity. Form: Injection. Route: Subcutaneous.
Scope: To improve muscle strength in adults and children with Barth syndrome who weigh at least 30 kg.
Published label: September 2025. https://www.accessdata.fda.gov/drugsatfda_docs/label/2025/215244s000lbl.pdf

Approval claim: “Forzinity is FDA-approved for a narrow Barth syndrome use.”
Verdict: Supported with scope. FDA granted accelerated approval for Forzinity to improve muscle strength in adults and children with Barth syndrome who weigh at least 30 kg. Accelerated approval uses an intermediate measure and requires a confirmatory study.
Evidence basis: Regulatory or product record. Scope: The Forzinity label and FDA approval records as reviewed August 30, 2026.
Claim sources: https://www.fda.gov/news-events/press-announcements/fda-grants-accelerated-approval-first-treatment-barth-syndrome https://www.accessdata.fda.gov/drugsatfda_docs/label/2025/215244s000lbl.pdf https://www.accessdata.fda.gov/drugsatfda_docs/appletter/2025/215244Orig1s000ltr.pdf

Sources used in the full review (a source is not support for every claim):

U.S. Food and Drug Administration. FDA identity record for elamipretide and SS-31. 2026. Accessed 2026-08-30. https://precision.fda.gov/uniisearch/srs/unii/87gwg91s09

U.S. Food and Drug Administration. FDA grants accelerated approval to Forzinity for Barth syndrome. 2025. Accessed 2026-08-30. https://www.fda.gov/news-events/press-announcements/fda-grants-accelerated-approval-first-treatment-barth-syndrome

U.S. Food and Drug Administration. Forzinity Drug Trials Snapshot. 2025. Accessed 2026-08-30. https://www.fda.gov/drugs/drug-trials-snapshots/drug-trials-snapshots-forzinity

U.S. Food and Drug Administration. Forzinity prescribing information. 2025. Accessed 2026-08-30. https://www.accessdata.fda.gov/drugsatfda_docs/label/2025/215244s000lbl.pdf

U.S. Food and Drug Administration. Forzinity FDA approval letter. 2025. Accessed 2026-08-30. https://www.accessdata.fda.gov/drugsatfda_docs/appletter/2025/215244Orig1s000ltr.pdf

PubMed. TAZPOWER randomized Barth syndrome study. 2020. Accessed 2026-08-30. https://pubmed.ncbi.nlm.nih.gov/33077895/

PubMed. MMPOWER-3 phase 3 mitochondrial-myopathy study. 2023. Accessed 2026-08-30. https://pubmed.ncbi.nlm.nih.gov/37268435/

PubMed. MMPOWER-2 mitochondrial-myopathy study. 2020. Accessed 2026-08-30. https://pubmed.ncbi.nlm.nih.gov/32096613/

PubMed. PROGRESS-HF elamipretide heart-failure study. 2020. Accessed 2026-08-30. https://pubmed.ncbi.nlm.nih.gov/32068002/

PubMed. Elamipretide study in healthy older adults. 2021. Accessed 2026-08-30. https://pubmed.ncbi.nlm.nih.gov/34264994/

ClinicalTrials.gov. TAZPOWER clinical study record. 2017. Accessed 2026-08-30. https://clinicaltrials.gov/study/NCT03098797

Keep the limits, review date, and sources with this record. Check the current source for changes.