SS-31 side effects and risks

Reported side effects

• Injection-site redness: Barth label: 12/12 (100%) active vs 3/12 (25%) placebo., mild. Rotate sites daily; avoid inflamed skin. (source)
• Injection-site pain: Barth label: 9/12 (75%) vs 5/12 (42%)., mild. Persistent or worsening reactions need review. (source)
• Injection-site firmness or itch: Each: 8/12 (67%) active vs 2/12 (17%) placebo., mild (source)
• Injection-site bruising or hives: Each: 3/12 (25%) active vs 0 placebo., moderate (source)
• Increased eosinophils, white blood cells: ReCLAIM 2: 7/117 (6.0%) vs 0/59 placebo. Label: frequent rises in studies lasting at least 30 days., mild (source)
• Serious allergic reaction: Can start minutes to months after treatment begins; frequency unknown., serious. Stop further doses and seek emergency care. (source)
• Flushing, dizziness or low blood pressure: Label overdose symptoms may be histamine related; community flushing has no reliable rate., moderate (source)
• Anxiety, stimulation or worsened fatigue: Personal reports only; frequency and causation are unknown., moderate (source)

Stop and get help if

• Trouble breathing, throat swelling, widespread hives or fainting after a dose: Stop further doses and seek emergency care now; a serious allergic reaction can need epinephrine.
• Marked lightheadedness, collapse or suspected overdose: Hold further doses and seek urgent medical assessment; overdose may cause low blood pressure.
• New severe or persistent abdominal pain, especially with vomiting: Seek urgent assessment; a pediatric report described pancreatic-enzyme elevation, but causation is uncertain.
• Cloudy vial, particles, fever or spreading hot, painful injection-site redness: Do not use the vial; seek prompt care for possible infection or product contamination.

Who should avoid it

• pregnant: No human pregnancy data. the FDA label does not list pregnancy as a formal contraindication.
• breastfeeding: No human milk or infant-effect data.
• tryingToConceive: Human reproductive safety is unknown.
• under18: The FDA label separately allows Barth syndrome patients weighing at least 30 kg.
• other: Do not restart after a serious allergy to elamipretide or a product ingredient.
• other: Safety and effectiveness below 30 kg are not established; no approved dose exists for this weight group.
• kidneyDisease: Kidney disease raises drug levels. Adults with estimated filtration below 30 mL/min need dosing review; dialysis dosing is unknown.
• heartCondition: Heart-failure trials do not establish general benefit. New chest pain, fainting or worsening breathlessness need prompt care.
• liverDisease: No liver dosing study was found. The label expects little change in drug levels; severe disease needs review.
• testedAthlete: Elamipretide is not named in the 2026 list. Its post-approval classification is unconfirmed; ask the sport’s anti-doping authority.

Interactions

• Aspirin and clopidogrel: Single-dose IV studies found no significant change in drug levels or blood-thinning effects. Other blood thinners remain uncertain.
• Unfractionated heparin: The IV study found no significant change in clotting tests, aPTT and anti-Xa. Continue usual monitoring.
• Metformin and other MATE1 substrates: In lab tests, elamipretide blocks MATE1, a protein that moves medicines. Effects on metformin in people remain unknown.
• Duplicate elamipretide products: These names mean the same peptide. Combining them can duplicate the dose. Do not mix products in one syringe.
• MOTS-c and other experimental energy stacks: No controlled human combination trial was found. Multiple changes make side effects and benefits hard to trace.

Product quality risks

• FDA documented mislisting and quality-control failures in an API supply chain that included elamipretide acetate; this did not measure all retail SS-31 vials.
• Unknown powders can have the wrong identity, amount or impurities; HPLC purity alone does not prove sterility or absence of bacterial toxins.
• No independent SS-31 retail-vial assay survey or confirmed SS-31 counterfeit-product series was located. Generic peptide warnings are not SS-31 incidence data.