SS-31
Mitochondria-targeted tetrapeptide · Elamipretide. Also written MTP-131 or Bendavia
- UK status
- Not licensed in the UK
- Availability
- Clinical trials, and grey market
- Evidence base
- Human RCT, no approval
- Controlled drug
- No
Sequence
A four amino acid peptide carrying a positive charge that concentrates it in mitochondria.
The short version
What it does
In trials, aimed at rare inherited diseases where the parts of your cells that make energy do not work properly. Sold online for tiredness, ageing and recovery.
How it does it
Carries a positive charge that pulls it into mitochondria, the energy-producing parts of your cells. Once there it binds to a fat molecule in the mitochondrial membrane that has to be correctly arranged for energy production to work.
The catch
The real programme is in rare, severe, inherited disease. Being tired is not mitochondrial disease, and nothing has established that this helps a healthy person.
Everything below goes into the detail, with sources.
SS-31 is one of the few compounds in this register with a genuine, ongoing pharmaceutical programme behind it. That programme is in rare inherited mitochondrial disease. What it is sold for online is tiredness, and those are not the same thing.
At a glance
- Compound type
- Peptide, 4 amino acids
- Generic name
- Elamipretide
- Drug class
- Mitochondria-targeted peptide
- Developed by
- Stealth BioTherapeutics
- Route
- Injection under the skin, in trials
- Studied for
- Barth syndrome, primary mitochondrial myopathy, and eye conditions
- Approval status
- No MHRA authorisation. Check the current FDA position.
- Sold online for
- Anti-ageing, energy and recovery, none of which it was trialled for
- In sport
- Check the current WADA Prohibited List and UKAD.
01What it is
Mitochondria produce most of your cells' energy, and their inner membrane contains a distinctive fat molecule called cardiolipin. Cardiolipin has to be correctly arranged for the energy production machinery to work, and in several diseases it is not.
SS-31 is four amino acids carrying a positive charge, which causes it to concentrate inside mitochondria, where the electrical gradient draws it in. There it associates with cardiolipin, and the proposition is that this stabilises the membrane and restores energy production.
Most drugs cannot be aimed at a specific part of a cell. This one is aimed by physics: the charge does the work. That is genuinely elegant pharmacology and a reason the compound has been taken seriously by people who are not selling it.
02How it came about
SS-31 emerged from academic work on mitochondria-targeted peptides and was developed clinically as elamipretide by Stealth BioTherapeutics. It has been studied in Barth syndrome, a rare inherited condition affecting cardiolipin directly, in primary mitochondrial myopathy, and in certain eye conditions.
Its regulatory history has been complicated, with mixed trial results across indications. Anyone relying on its current status should check the FDA and MHRA directly rather than any summary, including this one.
03UK legal and licensing status
No MHRA marketing authorisation. It cannot lawfully be supplied for human use in the UK outside an authorised clinical trial. It is not a controlled drug, and it is sold as a research chemical.
Its regulatory position elsewhere has moved and may move again. Check primary sources for the current position.
04How it works
The positive charge concentrates it in mitochondria. There it associates with cardiolipin in the inner membrane, with the aim of restoring the membrane architecture that energy production depends on. Reported downstream effects include reduced oxidative stress and improved mitochondrial function.
05What it is not
Claims that attach themselves to this compound and do not hold up.
- Not licensed in the UK for anything.
- Not studied for ageing, fatigue or recovery in healthy people. Its programme is in rare inherited disease.
- Not a fix for being tired. Mitochondrial disease is a specific set of diagnosable conditions, and everyday tiredness is not one of them.
- Not the same as MOTS-c or humanin. Those are peptides your mitochondria produce. This is a synthetic peptide aimed at mitochondria. Different things entirely.
06What the evidence shows
There are genuine randomised controlled trials in humans, which puts SS-31 well ahead of most compounds sold as research chemicals. Results across indications have been mixed, which is the honest summary and the reason its regulatory path has been difficult.
Rare disease trials are small by necessity, which makes them vulnerable to chance in both directions. A mixed record can mean a modest real effect that is hard to demonstrate, or no effect. Distinguishing those requires more data than exists.
What it definitely does not mean is that the compound has been shown to help a healthy adult with low energy. No trial has asked that question.
Any evidence in people without mitochondrial disease. Long-term safety outside supervised trials. And because grey-market product is unverified, whether what is being sold is even the right molecule.
07Reported harms
Trial reporting describes injection site reactions as the most common issue, which is consistent with a subcutaneous peptide. Without a licence there is no authoritative frequency table and no Yellow Card coverage.
The general point applies with force here: a compound with a plausible mechanism and real trials is not therefore safe to self-administer from an unverified source at a dose nobody established.
08Interactions and cautions
No UK SPC to consult. Interactions were managed by clinicians in the trials.
09Stopping
Not documented outside trial protocols.
10Monitoring
In trials, extensively, including disease-specific measures. Outside them, nothing. There is no test a person can get that would tell them whether this is doing anything.
11Questions worth asking
Take these to a doctor or pharmacist. A good clinician will not mind being asked, and the answers are specific to you in a way nothing on this page can be.
- Do I have a diagnosed mitochondrial condition, or am I treating tiredness?
- If I am persistently exhausted, has anyone investigated why?
- Is there a trial recruiting for the condition I actually have?
12Common questions
Is SS-31 the same as elamipretide?
Yes. SS-31 is the research designation; elamipretide is the generic name used in clinical development. It has also been called MTP-131 and Bendavia.
Does SS-31 help with fatigue or ageing?
Not established. Its clinical programme is in rare inherited mitochondrial conditions, not in healthy adults with low energy. No trial has tested the uses it is sold for online.
Is it approved anywhere?
It has no MHRA authorisation. Its status elsewhere has been complicated and has changed over time, so check the FDA and MHRA directly rather than relying on any summary.
How is it different from MOTS-c?
MOTS-c is a peptide encoded in your own mitochondrial DNA. SS-31 is a synthetic peptide designed to concentrate inside mitochondria and act on their membrane. Both involve mitochondria and they are otherwise unrelated.
13Sources
Links go to the authoritative source. Where a document sits behind a paywall or moves around, the full citation is given so you can find it yourself.
- Elamipretide clinical trial recordsClinicalTrials.gov
- SS-31 and cardiolipin, mechanism literaturePubMed
- Elamipretide trials in primary mitochondrial myopathyPubMed
- MOTS-c record/compounds/mots-c/
- Unlicensed medicines guidanceMHRA
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