R2 Medical Clinic

SS-31 (Elamipretide)

What Is SS-31?

SS-31, also known as Elamipretide, MTP-131, or Bendavia, is a synthetic mitochondria-targeted tetrapeptide developed to improve mitochondrial function by binding to cardiolipin, a phospholipid found exclusively in the inner mitochondrial membrane. Unlike most peptides that act through hormone receptors, SS-31 works directly within mitochondria to improve energy production and reduce oxidative stress.

The SS-31 tetrapeptide — D-Arg · Dmt · Lys · Phe — binds cardiolipin in the inner mitochondrial membrane.

SS-31 has been investigated for numerous diseases associated with mitochondrial dysfunction, including Barth syndrome, primary mitochondrial myopathy, heart failure, chronic kidney disease, age-related muscle dysfunction, neurodegenerative disease, and retinal disorders.

As of September 2025, elamipretide (brand name Forzinity®) received FDA accelerated approval for the treatment of Barth syndrome in patients weighing at least 30 kg, making it the first FDA-approved mitochondria-targeted therapeutic.

Mechanism of Action

Unlike growth hormone secretagogues or immune peptides, SS-31 acts directly within mitochondria.

Research suggests SS-31:

  • Selectively binds cardiolipin in the inner mitochondrial membrane
  • Stabilizes mitochondrial cristae structure
  • Improves electron transport chain efficiency
  • Reduces excessive production of reactive oxygen species (ROS)
  • Improves ATP production
  • Preserves mitochondrial membrane potential
  • Improves oxidative phosphorylation
  • Enhances mitochondrial bioenergetics
  • Improves ADP transport through the adenine nucleotide translocator (ANT)
  • Reduces mitochondrial dysfunction associated with aging and disease

Rather than acting as a conventional antioxidant, SS-31 appears to improve mitochondrial efficiency by preserving normal mitochondrial membrane architecture and optimizing energy production.

Potential Benefits

Published research suggests SS-31 may provide several biologic benefits related to mitochondrial function.

Potential benefits may include:

  • Improved mitochondrial energy production
  • Increased ATP synthesis
  • Reduced oxidative stress
  • Improved skeletal muscle function
  • Improved exercise tolerance
  • Support of cardiac mitochondrial function
  • Protection against ischemia-reperfusion injury
  • Support of kidney function in experimental models
  • Improved retinal mitochondrial function
  • Potential neuroprotective effects
  • Improved muscle endurance
  • Reduced fatigue associated with mitochondrial dysfunction

Many of these findings have been demonstrated in animal studies and early human clinical trials. Evidence varies by disease state, and several indications remain investigational.

Risks & Side Effects

SS-31 has generally demonstrated a favorable safety profile in clinical trials.

Reported adverse effects include:

  • Injection-site reactions
  • Mild injection-site pain
  • Redness
  • Bruising
  • Itching
  • Headache
  • Fatigue
  • Nausea
  • Dizziness

Serious adverse reactions have been uncommon in published clinical studies. The most frequently reported side effects in trials leading to FDA approval for Barth syndrome were mild-to-moderate injection-site reactions.

Contraindications

Formal contraindications remain limited because clinical experience is still evolving.

SS-31 should generally be used with caution in patients with:

  • Known hypersensitivity to elamipretide or formulation components
  • Pregnancy or breastfeeding (limited human safety data)
  • Severe uncontrolled systemic illness unless supervised by a specialist
  • Participation in investigational therapies without physician oversight

Patients with complex cardiovascular, renal, neurologic, or mitochondrial disorders should be managed by clinicians experienced in these conditions.

FDA Approval Status

United States

Elamipretide (Forzinity®) received FDA accelerated approval on September 19, 2025 as the first treatment for Barth syndrome in patients weighing at least 30 kg. The approval was based on improvement in knee extensor muscle strength, with a post-marketing confirmatory trial required to verify clinical benefit.

Outside of Barth syndrome, SS-31 is not FDA-approved for:

  • Anti-aging
  • Athletic performance
  • Fatigue
  • Heart failure
  • Chronic kidney disease
  • Neurodegenerative disease
  • Primary mitochondrial myopathy
  • General mitochondrial dysfunction
  • Longevity therapy

Most other uses remain investigational.

Human & Animal Studies

Human Studies

SS-31 has been evaluated in numerous Phase I, II, and III clinical trials.

Human studies have investigated SS-31 for:

  • Barth syndrome
  • Primary mitochondrial myopathy
  • Heart failure
  • Age-related muscle dysfunction
  • Chronic kidney disease
  • Retinal disease
  • Mitochondrial disorders

Clinical research has demonstrated:

  • Improved mitochondrial ATP production
  • Improved skeletal muscle bioenergetics
  • Improved muscle performance in selected populations
  • Favorable safety profile across multiple clinical trials

The strongest current clinical evidence exists for Barth syndrome, which resulted in FDA accelerated approval.

Animal & Preclinical Studies

Extensive laboratory and animal studies have shown that SS-31 may:

  • Improve mitochondrial respiration
  • Increase ATP production
  • Reduce mitochondrial ROS generation
  • Improve cardiac function following ischemic injury
  • Improve skeletal muscle performance
  • Protect kidney tissue from injury
  • Improve retinal mitochondrial function
  • Improve cognitive function in experimental neurodegenerative models
  • Restore mitochondrial function associated with aging

Recent mechanistic work demonstrated that SS-31 improves ADP uptake through the adenine nucleotide translocator (ANT), restoring mitochondrial energy production in aged muscle.

Published Studies

Human Studies

  1. Elamipretide: A Review of Its Structure, Mechanism of Action, and Therapeutic Applications
    https://pmc.ncbi.nlm.nih.gov/articles/PMC11816484/
  2. The Mitochondrially Targeted Peptide Elamipretide (SS-31) Improves ADP Sensitivity in Aged Mitochondria by Increasing Uptake Through the Adenine Nucleotide Translocator (ANT)
    https://pubmed.ncbi.nlm.nih.gov/37462785/
  3. Application Research of Novel Peptide Mitochondrial Targeted Therapeutic Elamipretide
    https://pubmed.ncbi.nlm.nih.gov/38237649/

Animal & Preclinical Studies

  1. Elamipretide Improves Mitochondrial Dysfunction, Synaptic Function, and Memory Impairment Induced by Lipopolysaccharide in Mice
    https://pubmed.ncbi.nlm.nih.gov/31747905/
  2. SS-31, a Mitochondria-Targeting Peptide, Ameliorates Kidney Injury by Reducing Oxidative Stress and Improving Mitochondrial Function
    https://pmc.ncbi.nlm.nih.gov/articles/PMC9192202/
  3. The Mitochondrially Targeted Peptide Elamipretide Improves ADP Sensitivity in Aged Mitochondria
    https://pmc.ncbi.nlm.nih.gov/articles/PMC10643647/

FDA / Regulatory Sources

  1. FDA Grants Accelerated Approval to First Treatment for Barth Syndrome (Forzinity® / Elamipretide)
    https://www.fda.gov/news-events/press-announcements/fda-grants-accelerated-approval-first-treatment-barth-syndrome
  2. ClinicalTrials.gov – Elamipretide Clinical Studies
    https://clinicaltrials.gov/search?term=elamipretide

Review Articles

  1. Elamipretide: A Review of Its Structure, Mechanism of Action, and Therapeutic Applications
    https://pmc.ncbi.nlm.nih.gov/articles/PMC11816484/
  2. Application Research of Novel Peptide Mitochondrial Targeted Therapeutic Elamipretide
    https://pubmed.ncbi.nlm.nih.gov/38237649/
  3. First-in-Class Cardiolipin-Protective Compound as a Therapeutic Agent to Restore Mitochondrial Bioenergetics
    https://bpspubs.onlinelibrary.wiley.com/doi/full/10.1111/bph.12461

The information provided on this page is intended for educational and informational purposes only. It is not intended to diagnose, treat, cure, or prevent any disease and should not be considered medical advice.

This content was generated with the assistance of artificial intelligence (AI) and should be reviewed by a qualified medical professional before publication or clinical use. AI-generated medical content may contain errors, omissions, or outdated information.

SS-31 (elamipretide) received FDA accelerated approval in 2025 for the treatment of Barth syndrome. Most other proposed uses remain investigational and are not FDA-approved. Individual results vary, and no specific outcome or benefit can be guaranteed. Patients should consult a qualified healthcare provider before beginning or changing any medical treatment.

R2 Medical Clinic uses medications sourced from compounding pharmacies. Compounded medications are not approved by the U.S. Food and Drug Administration (FDA). Unlike FDA-approved medications, compounded drugs have not undergone FDA review for safety, effectiveness, or efficacy through the FDA drug approval process. While 503B outsourcing facilities are registered with and inspected by the FDA and must comply with Current Good Manufacturing Practice (CGMP) requirements, the compounded medications they produce are not individually approved by the FDA. Similarly, compounded medications prepared by 503A pharmacies are not FDA-approved and are primarily regulated by state boards of pharmacy, with FDA oversight under applicable federal law.

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