Peptide research profile

SS-31 (elamipretide): mitochondrial targeting, trials, and narrow regulatory context

SS-31 is a synthetic mitochondria-targeted tetrapeptide developed as elamipretide. Its evidence spans mechanism studies and indication-specific human trials, including a randomized Barth syndrome program whose primary period and later extension require separate interpretation.

Published by PeptideSchool Editorial DeskPublished 2026-08-11Reviewed 2026-08-11

Educational content only. Not medical advice.

A synthetic mitochondria-targeted tetrapeptide

SS-31 is a synthetic four-amino-acid peptide known in clinical development as elamipretide. It is studied for localization to the inner mitochondrial membrane and interactions associated with cardiolipin, a phospholipid important to membrane organization and respiratory-chain function.

Mechanistic studies support hypotheses about membrane structure, energetics, and oxidative processes. They do not establish a clinical benefit across every disease in which mitochondrial dysfunction appears. The relevant disease mechanism and controlled outcome remain essential.

What the Barth syndrome trial reported

A phase 2/3 program in people with genetically confirmed Barth syndrome used a randomized, double-blind, placebo-controlled crossover period followed by an open-label extension. The randomized primary period did not show statistically significant differences for its primary endpoints. Later open-label observations suggested changes over longer exposure but lacked a concurrent placebo control.

Those periods answer different questions and should not be blended. A negative randomized primary comparison remains negative; an open-label extension can generate longer-term signals while remaining vulnerable to time effects, selection, expectation, and lack of control.

How later regulatory action should be framed

The FDA later announced accelerated approval of elamipretide for a narrowly defined Barth syndrome population. Accelerated approval and its supporting endpoint, conditions, labeling, and required confirmatory evidence must be described from the current official record. The decision does not retroactively make the randomized primary endpoints positive.

A regulator action for one rare genetic condition does not establish benefit for general mitochondrial health, exercise, aging, heart disease, or unrelated disorders. Product, indication, age range, jurisdiction, and date belong in the same sentence as approval status.

What remains outside the evidence

Research continues across mitochondrial and age-associated conditions, but each program needs its own evidence appraisal. It is unsafe to generalize from cardiolipin biology or a Barth syndrome decision to untested wellness outcomes.

This public profile provides no protocol, dosage, reconstitution, administration, acquisition, or off-label guidance. Its purpose is to show how mechanism, a mixed trial record, and a narrow regulator decision can all be true at the same time.

Evidence limits

  • The cited human evidence is indication-specific and cannot support broad mitochondrial wellness claims.
  • Open-label extension observations have weaker causal control than the randomized comparison.
  • Approval scope and post-approval requirements must be checked in the current official label and regulator record.

Sources and further reading

These sources ground the definitions and evidence boundaries on this page. A citation is a route for verification, not an endorsement of a product or personal use.

Genetics in Medicine

A phase 2/3 randomized clinical trial followed by an open-label extension to evaluate elamipretide in Barth syndrome

Randomized human evidence used to illustrate indication-specific outcomes and trial interpretation.

Open source

U.S. Food and Drug Administration

FDA Grants Accelerated Approval for First Treatment for Barth Syndrome

Official source for the date, pathway, product, and narrow indication of the regulatory decision.

Open source

U.S. National Library of Medicine

ClinicalTrials.gov Glossary Terms

Official definitions for randomized, open-label, primary outcome, phase, and study-status terms.

Open source

Common questions

Are SS-31 and elamipretide the same molecule name?

SS-31 is the research name commonly used for the synthetic tetrapeptide developed clinically as elamipretide.

Does an FDA decision for Barth syndrome prove general anti-aging effects?

No. The decision is tied to a defined product and rare-disease indication. Other outcomes and populations require their own controlled evidence.

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