Peptide · Fact sheet
Elamipretide
Also known as Forzinity · SS-31 · MTP-131 · Bendavia
Elamipretide is FDA approved only as Forzinity to improve muscle strength in adults and children with Barth syndrome who weigh at least 30 kilograms. That approval does not establish a general mitochondrial, energy, anti-aging, or muscle-performance therapy.
What is Elamipretide?
Elamipretide is a small manufactured peptide that binds cardiolipin, a lipid in the inner mitochondrial membrane.
Forzinity received accelerated approval based on improved knee-extensor muscle strength, an intermediate endpoint considered reasonably likely to predict clinical benefit.
Benefits people look for
It is the first FDA-approved treatment for Barth syndrome and one of the clearest examples of a mitochondria-targeting peptide reaching regulatory approval.
Broader mitochondrial-disease, heart, eye, fatigue, and healthy-aging claims remain separate research questions; a Phase 3 primary mitochondrial myopathy trial did not meet its primary endpoints.
What the evidence supports
- The approval program observed improvement in knee-extensor muscle strength in a small group with Barth syndrome.
- The larger MMPOWER-3 trial in primary mitochondrial myopathy did not show benefit over placebo for walking distance or fatigue at 24 weeks.
All research areas
- Barth syndrome
- Primary mitochondrial myopathy
- Mitochondrial function and muscle energetics
- Heart and eye disorders in clinical research
- Other mitochondrial diseases and genetically defined mitochondrial myopathies
- Cardiac, ophthalmic, and muscle-function outcomes outside the approved indication
Anecdotal reports & lived experiences
Reports describe what someone noticed. They cannot establish cause, typical results, or how often a side effect happens.
No attributable personal reports are summarized here yet. The benefits above describe research interests; the side effects below come from the cited medical sources.
We do not fill this gap with unsourced testimonials or estimated success rates.
Side effects & risks
- The current label identifies injection-site reactions as the most common adverse reactions.
- The formulation contains benzyl alcohol and carries a warning against use in neonates.
- Evidence from a small rare-disease population cannot characterize every uncommon or long-term harm.
This is a summary of the cited evidence, not a complete product label. A lack of human safety data does not establish safety.
Clinical research: how strong is it?
Moderate human evidenceThe approved claim rests on a very small rare-disease program and an intermediate endpoint. Evidence should not be generalized to other mitochondrial disorders or consumer performance goals, especially because MMPOWER-3 was negative on its primary endpoints.
Selected research to read
Registered post-marketing confirmatory trial for elamipretide in genetically confirmed Barth syndrome.
Phase 3 trial that did not meet its primary walking-distance or fatigue endpoints in primary mitochondrial myopathy.
What do the human studies show?
Selected research questions, not a complete inventory of indications or trials. Source checking is not independent clinical review. How we read the evidence.
| Study and people | Question and follow-up | Result and limits |
|---|---|---|
| MMPOWER-3 Genetically confirmed primary mitochondrial myopathy 218 participants (actual) Randomized placebo-controlled trial; human | Elamipretide versus Placebo 24 weeks Primary: Six-minute walking distance and disease-specific fatigue score Phase: Phase 3 | Neither primary endpoint was met. Walking-distance difference −3.2 m; 95% CI −18.7 to 12.3. Cannot tell us: Primary mitochondrial myopathy is not interchangeable with the approved Barth syndrome population. Safety, uncertainty, and source detailsMost reported events were mild or moderate; this does not establish safety for unrelated uses. Limited to the studied population, formulation and follow-up. Funding/conflicts: Author disclosures include industry grants, consulting and sponsor employees; see full paper. Source checked: 2026-09-18. Independent clinical review: not completed. |
What these results can and cannot tell us
Why does Barth syndrome approval not establish benefit in all mitochondrial diseases?
Accelerated approval has a narrow Barth syndrome scope; MMPOWER-3 studied a different population and missed its primary endpoints.
Limit: Knee-strength surrogate evidence does not remove the need to confirm patient benefit.
Check the sources: MMPOWER-3: elamipretide in primary mitochondrial myopathy (checked 2026-09-18) · FDA accelerated approval: Forzinity for Barth syndrome (checked 2026-09-18)
What is approved, and for whom?
United States records selected for the questions above; not a complete label or a worldwide approval inventory.
Forzinity: Barth syndrome
Subcutaneous injection · Patients with Barth syndrome weighing at least 30 kg
accelerated approval — Confirmatory evidence of patient benefit is required. This is not approval for primary mitochondrial myopathy generally.
Exact linked source and stated indication only; not an exhaustive regulatory search.
Read the original source · Source checked: 2026-09-18 · Decision: 2025-09-19
Compare research questions · Submit a source-based correction
FDA approval & research status
FDA granted accelerated approval to Forzinity for improving muscle strength in adults and children with Barth syndrome weighing at least 30 kilograms. A post-marketing confirmatory trial is registered, and continued approval may depend on verification of clinical benefit.
Approved uses covered here
- Improving muscle strength in adults and children with Barth syndrome who weigh at least 30 kilograms under the Forzinity label
FDA accelerated approval granted
Elamipretide has FDA accelerated approval for Barth syndrome under the Forzinity label, with post-approval study obligations separate from broader mitochondrial or wellness claims.
This summarizes the cited product or research record. Trial phases do not establish successful completion of earlier stages, and a stopped program is not ongoing development. Approval applies only to the labeled product, use and population.
What we still don’t know
- Whether the registered confirmatory trial will verify a patient-centered clinical benefit in Barth syndrome
- Which, if any, other genetically defined mitochondrial disorders benefit
- Long-term safety across broader populations
- Whether laboratory or muscle-energy effects translate into meaningful outcomes outside the approved use
The takeaway
Elamipretide is a landmark mitochondrial peptide, but its accelerated approval is narrow and based on an intermediate endpoint. It is not proof of a general mitochondrial boost or performance benefit.
Sources & further reading
Medical evidence and regulatory sources are listed here. Personal reports are linked separately in the experiences section.
- 1fdaFDA prescribing information: Forzinity
Current approval scope, accelerated-approval basis, warnings, and adverse reactions.
- 2fdaFDA: accelerated approval for Barth syndrome
FDA announcement describing the accelerated-approval decision and required confirmatory research.
- 3clinical trialsClinicalTrials.gov: 4TAZPower
Registered post-marketing confirmatory trial for elamipretide in genetically confirmed Barth syndrome.
- 4pubmedMMPOWER-3 randomized clinical trial
Phase 3 trial that did not meet its primary walking-distance or fatigue endpoints in primary mitochondrial myopathy.