Hormones & metabolism Mitochondria-targeting tetrapeptide
Elamipretide
Regulatory status
Status at a glance
503A compounding status
Not nominated
We found no pending nomination for the 503A bulks list. Unless the substance has another legal pathway (for example, a USP monograph or use in an FDA-approved drug), 503A pharmacies generally may not compound with it.
- FDA approval
- An FDA-approved product contains this peptide
- 503B outsourcing
- Not determined
- Anti-doping (WADA)
- Not on the WADA Prohibited List
- DEA schedule
- Not a controlled substance
About peptide status
Most peptides discussed here are not FDA-approved for any use, and products labeled “research use only” are not for human use. Removal from Category 2 does not authorize compounding. PCAC votes are non-binding recommendations; FDA and HHS make the final decisions.
This is not medical or legal advice, and we do not publish dosing, sourcing or reconstitution information. Talk with a licensed clinician before using any peptide.
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Key takeaway
Elamipretide is a mitochondria-targeting peptide that binds cardiolipin, a key molecule in the energy-producing inner membrane of mitochondria, developed by Stealth BioTherapeutics. It received FDA accelerated approval in 2025 as Forzinity for Barth syndrome, a rare genetic disorder of cardiolipin, making it the first approved treatment for that condition. Its approval rests on a muscle-strength surrogate measure with a confirmatory trial still required, and its other studied uses remain investigational.
At a glance
- What it is
- A mitochondria-targeting tetrapeptide, sold as Forzinity
- Approved for
- Improving muscle strength in adults and children with Barth syndrome who weigh at least 30 kg (accelerated approval, 2025)
- Key fact
- It is the first approved treatment for Barth syndrome, and a confirmatory trial is required
- Route
- Subcutaneous injection, once daily
- Evidence strength
- FDA approved (for Barth syndrome)
Summary
Elamipretide is a mitochondria-targeting peptide with FDA accelerated approval for Barth syndrome. Learn how it works and what that approval does not show.
What is elamipretide?
Elamipretide is a small peptide designed to concentrate inside mitochondria, the energy-producing structures of cells, where it binds a membrane lipid called cardiolipin. It is developed by Stealth BioTherapeutics and is given by subcutaneous injection. Its approved use is Barth syndrome, a rare genetic disorder of cardiolipin that affects the heart, muscles, and immune system; it has also been studied in other mitochondrial and eye diseases, where it remains investigational.
How does elamipretide work?
Elamipretide binds cardiolipin in the inner mitochondrial membrane and helps stabilize the folded structure (cristae) where energy production takes place. By supporting that architecture, it is intended to improve the efficiency of the electron transport chain that generates ATP and to reduce harmful reactive oxygen species. In Barth syndrome, which is caused by mutations in the TAFAZZIN gene that disrupt cardiolipin remodeling, this mechanism is the rationale for treatment. Mechanism describes how the drug is thought to act, separate from the clinical outcomes that trials measure.
Is it FDA-approved?
Editor’s note
Status: Yes, for one use, through the accelerated pathway. The FDA granted elamipretide accelerated approval on September 19, 2025, as Forzinity, to improve muscle strength in adults and children with Barth syndrome who weigh at least 30 kg. It is the first approved treatment for the condition. The regulatory path was contentious: - An earlier submission was turned down after the drug missed a walking-distance endpoint. - The approval was ultimately based on a knee-extensor muscle-strength measure. - A confirmatory randomized trial was required after approval. Its other studied uses are not approved.
Category: In clinical trials · Primary body area: Hormones & metabolism
Yes, for one use, through the accelerated pathway. The FDA granted elamipretide accelerated approval on September 19, 2025, as Forzinity, to improve muscle strength in adults and children with Barth syndrome who weigh at least 30 kg. It is the first approved treatment for the condition. The regulatory path was contentious:
- An earlier submission was turned down after the drug missed a walking-distance endpoint.
- The approval was ultimately based on a knee-extensor muscle-strength measure.
- A confirmatory randomized trial was required after approval.
Its other studied uses are not approved.
What is elamipretide prescribed for?
Elamipretide is prescribed to improve muscle strength in adults and children with Barth syndrome who weigh at least 30 kg, under specialist care. It is not approved for the other conditions in which it has been studied, such as dry age-related macular degeneration or primary mitochondrial myopathy, where trials did not lead to approval.
What are the side effects?
According to the prescribing information, the most common side effects are:
- Injection-site reactions such as redness, pain, hardening, itching, bruising, and hives
More serious considerations include:
- Serious allergic reactions
- A benzyl alcohol preservative, so it is not approved for newborns
Sources: the 168-week open-label extension of the TAZPOWER trial (Thompson et al., Genetics in Medicine, 2024, DOI: 10.1016/j.gim.2024.101138) and a related outcomes analysis (Gwaltney et al., Orphanet Journal of Rare Diseases, 2025, DOI: 10.1186/s13023-025-03693-5), both indexed on PubMed; and FDA prescribing information for Forzinity. This document is educational and does not constitute medical advice.
Registered human trials
0 registered human trials on ClinicalTrials.gov that we reviewed
Sources
- [1]
- [2]
- [3]
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