Peptides explained
SS-31: how it works
Also known as: Elamipretide
Page updated · Sources and editorial approach
SS-31, or elamipretide, targets mitochondrial cardiolipin. Learn about the specific US Forzinity approval and why it does not establish general longevity benefits.
SS-31 at a glance
What it does biologically
Elamipretide interacts with cardiolipin, a lipid in the inner mitochondrial membrane.
What the evidence shows
The specific medicine Forzinity received US accelerated approval for a defined Barth syndrome population in 2025.
What remains uncertain
That decision does not establish anti-ageing, athletic-performance or broad mitochondrial-health benefits, or equivalence of research-labelled SS-31.
The basics
What is SS-31?
SS-31 is a name used for elamipretide, a mitochondria-targeting peptide. Its clinical development includes rare mitochondrial disease rather than a universal energy or longevity indication.
In September 2025 the FDA granted accelerated approval to the specific medicine Forzinity to improve muscle strength in people with Barth syndrome weighing at least 30 kg. US approval of that product does not confer UK authorisation or pharmaceutical equivalence on separately supplied research material.
Biological action
How does SS-31 work?
Cardiolipin helps organise the inner mitochondrial membrane and its energy-related machinery. Elamipretide is described in the authorised US label as a mitochondrial cardiolipin binder.
A plausible mitochondrial mechanism needs condition-specific human testing. Improvement in one endpoint in a rare disease does not show that healthy people will have more energy, perform better or age more slowly.
Questions being investigated
What do studies examine?
Barth syndrome
The US indication concerns muscle strength in a defined rare-disease population.
Mitochondrial membrane biology
Cardiolipin binding is different from supplying a metabolic coenzyme such as NAD+.
Confirmatory evidence
Accelerated approval can depend on later verification of clinical benefit.
Strength of evidence
How strong is the evidence?
Evidence is separated by level because a cell experiment, an animal model, a human trial and a regulatory decision answer different questions.
| Evidence type | What it tells us |
|---|---|
| Laboratory | Cardiolipin-related pharmacology underlies the mitochondrial target. |
| Animal | Animal findings cannot establish general human performance or ageing benefits. |
| Human | The approval relied on an intermediate muscle-strength endpoint in a small rare-disease programme. |
| Regulatory | Forzinity has a specific US accelerated approval; the authorised label states the population and limits. |
Important context
Risks, limitations and unanswered questions
- Accelerated approval is not a finding that every proposed benefit is proven.
- The disease, product and clinical endpoint matter.
- The label includes product-specific adverse effects and precautions.
- A research-labelled vial is not automatically the approved medicine.
Reading the original evidence
Specify the country, product and authorisation route
The FDA announcement concerns accelerated US approval of Forzinity for Barth syndrome. That is a specific regulatory decision, not approval of every SS-31-labelled preparation or of general anti-ageing claims. An authorisation in one country also does not establish authorisation in another.
Question to take to the source: Does an approval claim name the exact product, indication, country and conditions of the decision?
Check the original source ↗For personal accounts and research questionnaires, read user feedback and patient-reported outcomes.
Questions answered
SS-31 FAQs
Is SS-31 the same as MOTS-C?
No. They are different peptides with different targets and clinical evidence.
Is elamipretide approved for anti-ageing?
The cited US indication is Barth syndrome, not general anti-ageing.
What does accelerated approval mean?
It permits a specific indication based on an endpoint considered likely to predict benefit, with further verification potentially required.
Check the sources
Sources and further reading
Follow the original study or official information to check the population, methods and full results. Reviews and sponsor updates are labelled below.
- FDA: Forzinity approval announcement ↗Regulator's September 2025 explanation of the indication and evidence.
- Forzinity official US prescribing information ↗Product-specific indication, accelerated-approval qualification and safety information.
Educational information, prepared with AI assistance and not independently clinically reviewed. It is not personal medical advice or a treatment recommendation. Read the editorial policy or suggest a correction.