Overview

The most rigorously developed mitochondrial peptide, and a case study in how a real drug development program plays out: an approval in one ultra-rare disease, and several failed trials in the larger indications people actually want it for.

Limited or non-US approvalApproved for a single ultra-rare indication. Research-grade "SS-31" is a separate, unapproved product.

At a glance

Regulatory status	Approved in the US for Barth syndrome, an ultra-rare mitochondrial disorder. Trials in primary mitochondrial myopathy and dry AMD did not meet primary endpoints.
Drug class	Cardiolipin-targeting mitochondrial tetrapeptide
Route	Subcutaneous
Half-life	~2–4 hours
Evidence rating	4/5 Strong Evidence rating 4 out of 5: Strong Consistent human randomized trials, or approval outside the United States.
Studied in	Phase 3 trials in primary mitochondrial myopathy (MMPOWER-3), Barth syndrome (TAZPOWER and extension), dry age-related macular degeneration, and heart failure.

How it works

Concentrates in the inner mitochondrial membrane where it binds cardiolipin, stabilising cristae architecture and the electron transport chain supercomplexes. This improves ATP production efficiency and reduces electron leak and reactive oxygen species generation.

Evidence base

Rated 4 of 5 — Strong. Consistent human randomized trials, or approval outside the United States.

Multiple phase 3 trials — a genuinely rigorous program, including informative negative results.

Benefits & potential uses

Bars indicate how well each claim is supported: three = strong human evidence, two = moderate, one = preliminary or preclinical.

Approved for Barth syndrome Strong evidence

Regulatory approval based on functional improvement data in an ultra-rare mitochondrial cardiomyopathy — a real clinical result.
Well-defined molecular mechanism Strong evidence

Cardiolipin binding and cristae stabilisation are directly demonstrable, unlike most "mitochondrial support" claims.
Improved muscle strength signals Moderate evidence

Extension studies in Barth syndrome showed progressive improvement in muscle strength measures over long-term dosing.
Extensive safety database Strong evidence

Years of exposure across multiple trial programs.

Risks, cons & cautions

Bars indicate seriousness: three = serious or common, two = moderate, one = minor.

Failed its largest trials Serious

Did not meet the primary endpoint in primary mitochondrial myopathy or in dry AMD. Broad "mitochondrial health" benefit is not supported.
Injection-site reactions Moderate evidence

The most common adverse event, occurring in a majority of patients in some trials.
Very narrow approved indication Moderate evidence

Any use outside Barth syndrome is off-label and unsupported by positive trial data.
Cost and access Minor

Ultra-orphan drug pricing; not realistically accessible for wellness use.
Grey-market SS-31 Serious

"SS-31" sold as a research peptide is not the pharmaceutical product and carries no quality assurance.

Who should avoid it

Off-label use for general anti-aging — the trials that tested broader benefit were negative
Pregnancy (insufficient data)

If used under medical supervision, monitor

Injection-site assessment
Disease-specific functional measures

Commonly confused with

These mix-ups cause real harm — two products sold under one name, or two molecules whose effects run in opposite directions.

MOTS-c Research Use Only Evidence 1/5

Both marketed as mitochondrial peptides. Elamipretide completed multiple phase 3 trials and holds an approval for one ultra-rare disease; MOTS-c has never been given to humans in a controlled trial.

Compare side by side

Regulatory & legal status

Approved for a single ultra-rare indication. Research-grade "SS-31" is a separate, unapproved product.

Infographic

Elamipretide (SS-31) — benefits & risks at a glance Download SVG

Where to read further

We link to live literature searches rather than a frozen citation list, so you always see current results — including anything published after our last review.

mitochondriarare diseasecardiolipinapprovedfailed trials

Related peptides in Longevity & Mitochondrial

Terms used on this page

Phase 3 Trial: A Phase 3 trial is the large confirmatory study, powered for a prespecified clinical endpoint, on which a marketing application and the resulting product label are built.
Primary vs Secondary Endpoint: The primary endpoint is the single prespecified outcome a trial is powered and statistically budgeted for, while secondary endpoints are additional measures that support interpretation but cannot replace it.
Adverse Event (AE): An adverse event is any untoward medical occurrence in someone receiving a medicine, recorded whether or not the drug caused it, which is why an event table is not a harm table.

This page is educational information, not medical advice. It cannot account for your medical history, medications, or risk factors. Do not start, stop or change any treatment based on it. Speak to a qualified healthcare professional who knows your case.