1. What is it?
SS-31, or elamipretide, is a synthetic peptide that interacts with cardiolipin. This lipid is a component of the inner mitochondrial membrane, which is important for cellular energy production. SS-31 often appears in older laboratory papers, while elamipretide is used in clinical studies and medicine documents. Connecting the names helps explain the research history, but activity in mitochondria alone does not imply a universal health benefit. [190] [186]
2. Why do people turn to it?
Interest in SS-31 often concerns energy, physical functioning and ageing. The confirmed US approval is much more specific: Forzinity is used to improve muscle strength in adults and children with Barth syndrome weighing at least 30 kg. This is a rare genetic condition involving mitochondrial dysfunction. It is not an indication for ordinary tiredness, improving sports performance or preventing ageing in healthy people. [186] [188]
3. How does it work?
In laboratory studies, SS-31 bound to cardiolipin and helped preserve processes needed for electron transfer and ATP production. ATP is a compound that cells use to perform work. This sounds promising, but an experiment on a membrane or isolated mitochondria does not measure a person's physical function. To assess a treatment's usefulness, researchers need to examine outcomes such as strength, walking and daily functioning in patients with a specific condition. [190]
4. What do studies actually show?
The main Barth syndrome trial involved 12 men and boys. Its initial stage did not confirm the expected improvement in the main assessments of walking and fatigue. Further follow-up produced muscle-strength data that formed the basis of accelerated approval. In contrast, MMPOWER-3, involving 218 adults with other primary mitochondrial muscle diseases, did not achieve its planned six-minute walk and fatigue outcomes after 24 weeks. [187] [189]
5. What do we still not know?
Barth syndrome and other mitochondrial diseases are not a single condition. Findings in one group cannot simply be applied to another, especially healthy people. Small patient numbers and follow-up in which participants' treatment was known increase uncertainty. Accelerated approval means the regulator accepted a particular basis for its decision but requires further confirmation of clinical benefit. It does not end all research into the medicine's usefulness. Further follow-up must establish how measured changes affect patients' daily lives. [187] [186] [189]
6. What are the risks?
Forzinity's product information mainly describes injection-site reactions and the possibility of a serious allergic reaction. The medicine is intended for a defined patient group, with treatment managed in light of their health. Data on the approved product cannot be transferred to products of different quality or composition. Because rejuvenating effects have not been demonstrated, a favourable balance of expected benefits and risks has not been established for that purpose either. [186]
7. Is it an approved medicine?
The FDA approved Forzinity on 19 September 2025 for the limited indication described. In the EU, elamipretide has confirmed orphan designation for Barth syndrome. This supports rare-disease treatment development but is not marketing authorization. Checked EMA documents did not confirm European marketing approval. The US decision does not mean automatic availability of approved treatment in Poland. [187] [188]
8. What is new in research?
After US approval, studies confirming the benefits of treatment remain important. The European registry lists a further elamipretide trial in Barth syndrome, designated SPIBA401. The record describes a plan to assess effectiveness and safety, not an achieved result. Publication of the results and any regulatory decisions will matter to readers. Registering a protocol alone does not broaden indications or demonstrate benefit in people without the condition. [191] [186]
Where does this information come from?
References link to the publications and documents used. Each source includes its material type and what was reviewed; findings concern the substance, form and study population described.
Show sources and how they were checked
- FORZINITY (elamipretide) injection, for subcutaneous use: Prescribing Information
FDA; prescribing information from September 2025; indication, approval pathway, warnings and study descriptions reviewed. Accessed: 3 November 2026.
- Drug Trials Snapshots: Forzinity
FDA; approval on 19 September 2025; population, study course and basis for the decision reviewed. Accessed: 3 November 2026.
- Efficacy and Safety of Elamipretide in Individuals With Primary Mitochondrial Myopathy: The MMPOWER-3 Randomized Clinical Trial
Randomised phase 3 trial in 218 adults; published online 2 June 2023; PubMed abstract reviewed · DOI: 10.1212/WNL.0000000000207402. Accessed: 3 November 2026.
- EU/3/21/2430 - orphan designation for treatment of Barth syndrome
EMA; orphan designation dated 20.05.2021; full record read on 03.11.2026; not a marketing authorisation. Accessed: 03.11.2026.
- Targeting mitochondrial cardiolipin and the cytochrome c/cardiolipin complex to promote electron transport and optimize mitochondrial ATP synthesis
Laboratory studies of membranes and mitochondria; April 2014; PubMed abstract and experiment descriptions read · DOI: 10.1111/bph.12468. Accessed: 03.11.2026.
- A Phase 3b/4, Randomized, Double-Blind, Parallel-Group, Placebo-Controlled, Trial to Evaluate the Efficacy and Safety of Daily Subcutaneous Injections of Elamipretide in Patients with Genetically Confirmed Barth Syndrome
EU trial registry; record reviewed through the search index on 3 November 2026; EUCT 2025-523837-25-00, SPIBA401; protocol, not results. Accessed: 3 November 2026.