SS-31
Reviewed
Short answer
SS-31 and elamipretide are names for the same four-amino-acid peptide. FDA gave Forzinity accelerated approval. This path uses a result that may predict a benefit. Another study must check the benefit. Forzinity has one narrow use. It is for adults and children with Barth syndrome who weigh at least 30 kg. The main study had 12 people. Forzinity did not improve walking distance or fatigue compared with placebo. The approval does not apply to other uses or SS-31 products.
The Peptide Field explains research. Its pages are not independently medically reviewed, and they do not diagnose, prescribe, or recommend treatment.
Read the study findingsAlso known as Elamipretide · MTP-131 · Bendavia · OCUVIA · RX-31 · SS31 · Szeto-Schiller peptide
Part of Anti-aging and longevity peptides
Legal status Is SS-31 legal? See the status table
Study and product details
What it is
SS-31 is a short peptide with four amino acids. FDA's substance record maps SS-31 to elamipretide and related development names such as MTP-131 and Bendavia. Mitochondria are small parts of cells that help make energy. Elamipretide binds to a fat called cardiolipin inside them. Forzinity is the FDA-approved product name.
Type of peptide: Peptide that binds inside mitochondria. This describes what the substance is or how it works. It does not show that it is safe, effective, or approved.
What has been studied?
- Moderate: Useful evidence exists, but important limits remain.
- Strong: Several reliable sources describe this clearly.
FDA approval covers one rare disease and one muscle-strength measure. Results in other conditions have been mixed, including a negative phase 3 study.
The FDA label describes elamipretide's four-amino-acid sequence and its binding to cardiolipin inside mitochondria.
The approved label describes injection-site reactions and serious allergic reactions. It does not define the long-term risks of every SS-31 product.
High for the named Forzinity product; limited for research material or products sold under the SS-31 name.
Products with the same ingredient can differ.
The ingredient name does not tell you everything about a product. Check its other ingredients, its form, how it enters the body, and the use and people covered by the research or approval.
Forzinity
September 2025- Ingredients and form
- Injection
- How it enters the body
- Under the skin (subcutaneous)
- Use and people covered
- To improve muscle strength in adults and children with Barth syndrome who weigh at least 30 kg.
- Forzinity
- Improving muscle strength in adults and children with Barth syndrome who weigh at least 30 kg
What studies found
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.
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.
Which products do these findings apply to?
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.
Fact checks
6 statements checked. Read what the results mean.
“SS-31 and elamipretide are names for the same peptide.”
FDA's substance record lists SS-31 and elamipretide as synonyms. It also lists development names such as MTP-131 and Bendavia. A name match does not prove that an online vial has the same quality or product controls.
- What this answer is based on
- Official record or product label
- Limits of this answer
- FDA substance identity mapping; not a quality or product-equivalence finding.
Sources for this fact check (1)
“Forzinity is FDA-approved for a narrow Barth syndrome use.”
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.
- What this answer is based on
- Official record or product label
- Limits of this answer
- The Forzinity label and FDA approval records as reviewed August 30, 2026.
Sources for this fact check (3)
“The randomized Forzinity study clearly improved walking and fatigue.”
FDA says the randomized study did not show superiority to placebo on its initial walking and fatigue measures. The approval used a knee-extensor muscle-strength measure and later extension data.
- What this answer is based on
- Health results from a study with randomly assigned groups
- Limits of this answer
- The randomized Barth syndrome study and its defined measures; this does not establish a result for other diseases or products.
Sources for this fact check (2)
Show 3 more fact checks
“Elamipretide improved walking distance and fatigue in the large phase 3 mitochondrial-myopathy trial.”
The 24-week MMPOWER-3 trial did not meet its main goals for six-minute walk distance or fatigue compared with placebo.
- What this answer is based on
- Health results from a study with randomly assigned groups
- Limits of this answer
- The 218 adults with genetically confirmed primary mitochondrial myopathy studied in MMPOWER-3 for 24 weeks.
Sources for this fact check (1)
“SS-31 is proven to increase energy, reduce fatigue, or slow aging in healthy people.”
A small healthy-aging study measured a laboratory energy measure. It did not establish better daily energy, less fatigue, longer life, or slower aging.
- What this answer is based on
- No reliable studies showing this health result in people
- Limits of this answer
- Healthy older adults in the single study reviewed; a laboratory measure is not the same as a long-term health outcome.
Sources for this fact check (1)
“Every product sold as SS-31 is equivalent to Forzinity.”
Forzinity is a specific FDA-approved product. An ingredient name or research vial does not establish the same formulation, manufacturing controls, strength, sterility, or clinical evidence.
- What this answer is based on
- Official record or product label
- Limits of this answer
- The named Forzinity product compared with any other material sold under the SS-31 or elamipretide name.
Sources for this fact check (2)
Risks and 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.
This editorial review did not determine sport eligibility. Athletes must check the current prohibited list, Global DRO, and their governing body.
Reviewed .Check the rules for athletes ↗Terms used in the studies
- peptide
- a short chain of amino acids
- accelerated approval
- early approval based on a result that may predict benefit; a later study must confirm the benefit
- placebo
- an inactive treatment used for comparison
- randomized
- assigned to study groups by chance
- open-label
- a study in which people and researchers know which treatment was given
- formulation
- the ingredients and physical form of the finished product
- mechanism
- how a substance may cause a body change
- biomarker
- a body or lab measurement, not automatically a health benefit
Read the sources
Show 11 sources
Review history
Reviewed FDA's Forzinity approval, label, and trial summary, the FDA identity record, and randomized human studies in Barth syndrome, primary mitochondrial myopathy, heart failure, and healthy older adults.
Not independently medically reviewed. This page is not a dosing, sourcing, or treatment guide.
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