Elamipretide Reference

Plain English

What it is

Elamipretide, also called SS-31 or MTP-131, is a lab-made peptide that targets mitochondria, the tiny power plants inside cells. It sticks to a fat called cardiolipin in the mitochondria to help them stay stable and make energy. The FDA approved it in 2025 under the brand name FORZINITY.

What people use it for

Its only FDA-approved use is to improve muscle strength in people with Barth syndrome, a rare inherited disease that mainly affects boys and men. In the peptide and longevity community, people use it off-label for general anti-aging and to support mitochondria, which is not an approved or proven use.

What the science shows

The approval came through an early ('accelerated') pathway in Barth syndrome, and the company still has to run a follow-up trial to confirm the benefit. A separate large trial in a different mitochondrial muscle disease did not work and missed its main goals. There is no human evidence that it slows aging.

The catch

FORZINITY is a prescription drug cleared only for one rare disease, and its approval could be pulled if the confirmatory trial fails. The longevity and anti-aging use promoted in the community is off-label and unproven. Reported side effects include injection-site reactions and serious allergic reactions that can affect breathing.

Reference summary

Human clinical trial data exist across several mitochondrial-disease programs, and the Barth-syndrome program supported the FORZINITY accelerated approval. The community longevity / mitochondrial / anti-aging research use that pepSmart describes falls outside that narrow approved indication; pepSmart displays elamipretide as trial-context and off-label educational content and does not imply approved use for those purposes.

Regulatory and posture

Categories

Longevity, Metabolic

Aliases

SS-31, MTP-131, Bendavia, D-Arg-Dmt-Lys-Phe-NH2

Evidence posture

human - FDA-approved only for Barth syndrome muscle weakness (FORZINITY, accelerated approval, September 2025). The broad primary-mitochondrial-myopathy program received a Complete Response Letter, and the longevity / research use described here is off-label and unvalidated.

Regulatory status

FDA-approved for a narrow rare-disease indication. Elamipretide (SS-31 / MTP-131), a cardiolipin-binding mitochondrial peptide developed by Stealth BioTherapeutics, received FDA accelerated approval as FORZINITY in September 2025 to improve muscle strength in adult and pediatric patients weighing at least 30 kg with Barth syndrome, the first approved therapy for that ultra-rare mitochondrial disease. Continued approval may be contingent on confirmatory-trial verification. The separate primary-mitochondrial-myopathy program received an FDA Complete Response Letter and is not approved.

Content review status

label verified

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