What it is
SS-31, now known by the drug name elamipretide, is a small peptide that targets the inner membrane of mitochondria. It binds to cardiolipin, a fat that helps mitochondria make energy.
By stabilizing cardiolipin, it is thought to help mitochondria work better and reduce harmful by-products. It was developed by Stealth BioTherapeutics.
US regulatory status
FDA-approved under accelerated approval (as Forzinity) in September 2025 to improve muscle strength in people with Barth syndrome who weigh at least 30 kg; continued approval depends on confirmatory studies. It is not approved for anti-aging or other uses.
What the research shows
Approval was based on improvements in a muscle strength measure in a small group of people with Barth syndrome, a rare genetic mitochondrial disease. Trials in other conditions, such as primary mitochondrial myopathy and some eye and heart diseases, have had mixed results.
How it is given
Subcutaneous injection
Commonly reported side effects
- Injection site reactions (pain, redness, itching, bruising)
- Injection site swelling or hardening
- Headache
- Limited long-term data
Questions to ask your provider
- Does my diagnosis fit the approved use of elamipretide?
- How will we measure whether it is helping me?
- Are there clinical trials for my mitochondrial condition?