Library / Longevity

SS-31

Also known as Elamipretide, Forzinity, MTP-131, Bendavia

Approved medicine

Mitochondria targeted tetrapeptide that binds cardiolipin in the inner mitochondrial membrane. Approved only for the rare genetic disorder Barth syndrome; a trial in primary mitochondrial myopathy did not meet its primary endpoints.

Not approved in Australia. SS-31 is not on the Australian Register of Therapeutic Goods. Only a prescriber can decide whether a medicine suits you and at what dose. This page is information, not a recommendation.

Background

Small four amino acid peptide from the Szeto-Schiller series, discovered by Hazel Szeto and Peter Schiller and developed as elamipretide by Stealth BioTherapeutics. The FDA gave it accelerated approval as Forzinity in September 2025 for Barth syndrome.

How it is thought to work

Enters cells and binds cardiolipin, a fat in the inner membrane of mitochondria. This is thought to stabilise the energy producing machinery, improve ATP production and reduce harmful oxidation.

What is claimed, and the evidence

Claim	Evidence	Notes
Improves muscle strength in Barth syndrome (weight 30 kg or more)	Approved use	US accelerated approval based on knee extensor strength in 12 patients; continued approval depends on a confirmatory trial.
Improves walking and fatigue in primary mitochondrial myopathy	Human trials Not supported	The phase 3 MMPOWER-3 trial in 218 people did not meet its primary endpoints.
Improves heart failure	Small human studies	Animal studies positive; early phase human studies showed some haemodynamic changes but no proof of benefit.
Treats dry age related macular degeneration	Small human studies	In phase 3 development; no approval.
Reverses ageing or boosts energy in healthy people	Animal studies only	Aged animal studies only; marketed online as anti ageing without human evidence.

Side effects

Effect	How often	Notes
Injection site reactions (redness, pain, hardening, itch, bruising, hives)	Common	All 12 Barth patients had local reactions on the drug versus 67% on placebo (label).
Raised eosinophil count	Common	Label notes frequent rises with use over 30 days, generally returning to baseline.
Serious allergic reactions Serious	Rare	Label warns of hypersensitivity reactions requiring emergency treatment.
Benzyl alcohol toxicity in newborns Serious	Rare	Label warning; the product contains benzyl alcohol and is not approved in neonates.

Warnings

Approved only for Barth syndrome under accelerated approval; a large trial in mitochondrial myopathy failed.
Safety data come from small numbers of patients, mostly with rare diseases.
Not found on the Australian Register of Therapeutic Goods.
Unapproved products are not made to medicine standards and may be contaminated, underdosed, overdosed or contain a different substance from the label; the TGA warns that injected unapproved peptides carry risks including contamination, infection and local tissue damage.

Regulatory status

Australia: Not found on the ARTG. Not specifically listed in the Poisons Standard (June 2026).
United States: FDA accelerated approval (Forzinity, September 2025) to improve muscle strength in Barth syndrome in patients weighing at least 30 kg.

Sources

Also in Longevity

From the VialOwl library, reviewed 26 September 2026. For education and general information. It is not medical advice and not a recommendation to use SS-31.