Evidence brief
SS-31
Written and source-checked by Anthony Treviso, founder of The Peptide Field.
Direct 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.
SS-31 is elamipretide. FDA approved Forzinity for one narrow use, not for anti-aging.
- How strong is the evidence?
- Established
An official agency review or strong, repeated studies in people support one clear use. That evidence applies only to the product, people, and use we reviewed. It does not mean the product is safe or effective for everyone. - What evidence exists?
- Approved human outcomes
Approved products have evidence from studies in people that measured health results for specific uses. This does not show that every product, person, or use has the same result. - Sports rules
- Not assessed
No current sports-rule review is available.
Reviewed August 30, 2026. Sources and update notes are below.
No sales or dosing advice. This guide explains research. It was not independently medically reviewed, and it does not diagnose, prescribe, or recommend treatment.
Also known as Elamipretide · MTP-131 · Bendavia · OCUVIA · RX-31 · SS31 · Szeto-Schiller peptide
Words used here
- 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
- outcome
- what the study measured
- 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
More detailProduct and study details
01 · Evidence profile
Four questions about the evidence
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.
02 · Identity
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.
Scientific group: Peptide that binds inside mitochondria. This group name describes the type of molecule or body signal. It does not prove a benefit, safety, or approval.
03 · Exact product
The molecule is not the finished product.
Formulation: The finished product's ingredients and physical form. Route: How the product enters the body. Indication: The approved or studied use and group of people for a product.
Forzinity
September 2025- Formulation
- Injection
- Route
- Subcutaneous
- Indication scope
- 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
04 · Research results
What the research 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.
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.
Exact product
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.
05 · Claim check
Claims I checked
6 claims checked for this brief.
“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.
- Evidence used
- Regulatory or product record. This answer uses an official regulator record or a specific product label.
- Limits of this answer
- FDA substance identity mapping; not a quality or product-equivalence finding. This answer covers only the named molecule and finished product. It also covers the product form and how people used it. The study limits include who took part, what was used for comparison, what changed, and how long the study lasted.
“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.
- Evidence used
- Regulatory or product record. This answer uses an official regulator record or a specific product label.
- Limits of this answer
- The Forzinity label and FDA approval records as reviewed August 30, 2026. This answer covers only the named molecule and finished product. It also covers the product form and how people used it. The study limits include who took part, what was used for comparison, what changed, and how long the study lasted.
“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.
- Evidence used
- Randomized human outcomes. This answer uses a study that assigned people to groups by chance and measured a health outcome.
- Limits of this answer
- The randomized Barth syndrome study and its defined measures; this does not establish a result for other diseases or products. This answer covers only the named molecule and finished product. It also covers the product form and how people used it. The study limits include who took part, what was used for comparison, what changed, and how long the study lasted.
Show 3 more claim 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.
- Evidence used
- Randomized human outcomes. This answer uses a study that assigned people to groups by chance and measured a health outcome.
- Limits of this answer
- The 218 adults with genetically confirmed primary mitochondrial myopathy studied in MMPOWER-3 for 24 weeks. This answer covers only the named molecule and finished product. It also covers the product form and how people used it. The study limits include who took part, what was used for comparison, what changed, and how long the study lasted.
“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.
- Evidence used
- No reliable human outcome evidence. No reliable study in people shows the health outcome in this statement.
- 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. This answer covers only the named molecule and finished product. It also covers the product form and how people used it. The study limits include who took part, what was used for comparison, what changed, and how long the study lasted.
“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.
- Evidence used
- Regulatory or product record. This answer uses an official regulator record or a specific product label.
- Limits of this answer
- The named Forzinity product compared with any other material sold under the SS-31 or elamipretide name. This answer covers only the named molecule and finished product. It also covers the product form and how people used it. The study limits include who took part, what was used for comparison, what changed, and how long the study lasted.
06 · Questions
Questions people ask about SS-31
FDA approved the specific Forzinity product under accelerated approval for one narrow Barth syndrome use in people weighing at least 30 kg. A later study must confirm a patient benefit. This approval does not cover broader uses or other SS-31 products.
Not assessed. This editorial review did not determine sport eligibility. Athletes must check the current prohibited list, Global DRO, and their governing body. This status is not personal clearance to compete.
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.
07 · Safety
Safety limits for this record
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.
No current sports-rule review is available.
Reviewed .Check current rules for tested sport ↗08 · Sources
Read the sources
09 · Review history
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.
Written and source-checked by Anthony Treviso, founder of The Peptide Field.
Not independently medically reviewed. This page is not a dosing, sourcing, or treatment guide.