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Dosage information

SS-31 dosage

The only established SS-31 dosage is the FDA label dose of Forzinity (elamipretide) for Barth syndrome, set by the prescriber.1 It is 40 mg under the skin once daily for patients weighing at least 30 kg.1 Trial doses were research protocols, and no dose is established for any other use.1

This page summarizes published sources for information only. It is not medical advice and does not tell anyone to use a product. Questions about your own health belong with a licensed clinician. For questions about an order or a product, contact us.

The label dose

The prescribing information for Forzinity, approved by FDA under NDA 215244, holds the only established human dose of elamipretide.111 The prescriber sets the dose. Adult patients or caregivers may give it after training, if a healthcare provider decides that is appropriate, with medical follow-up as needed.1 The label covers one use, improving muscle strength in Barth syndrome, for patients of 30 kg or more.1

Patient group Label dose How it is given
Barth syndrome, 30 kg or more 40 mg once daily1 Under the skin (subcutaneous), at the same time each day1
Adults with eGFR below 30 mL/min, not on dialysis 20 mg once daily1 Under the skin1
Adults with eGFR below 30 mL/min, on dialysis No dose recommended (too little information)1 Not applicable
Children of 30 kg or more with kidney impairment No dose recommended1 Not applicable
Patients under 30 kg Safety and effectiveness not established1 Not applicable

Two more label points concern dosing. A missed dose is skipped rather than doubled, and the next dose is taken at the usual time.1 Forzinity is not approved for use in a vein.1

Doses used in clinical trials

These doses come from published trials and trial registries. Each was a research protocol run under medical supervision for a specific disease. None is guidance for a person, and results for each trial are on SS-31 benefits and uses.

Trial (phase) Participants Dose and route Length
TAZPOWER (2/3)12 12 males with Barth syndrome 40 mg/day under the skin 12 weeks per crossover period; extension up to 192 weeks1
MMPOWER (1/2)6 36 adults with primary mitochondrial myopathy 2-hour infusion into a vein at 0.01, 0.1 or 0.25 mg/kg/h 5 days
MMPOWER-2 (2)8 30 adults with primary mitochondrial myopathy 40 mg/day under the skin 4 weeks per crossover period
MMPOWER-3 (3)13 218 adults with primary mitochondrial myopathy 40 mg/day under the skin 24 weeks
NuPOWER (3)3 102 adults with nuclear DNA mitochondrial disease 60 mg once daily under the skin 48 weeks
PROGRESS-HF (2)2 71 patients with heart failure 4 mg or 40 mg once daily under the skin 28 days
Heart failure infusion trial5 36 adults with heart failure 4-hour infusion at 0.005, 0.05 or 0.25 mg/kg/h One infusion
EMBRACE STEMI (2a)7 Adults with a first anterior heart attack Infusion at 0.05 mg/kg/h for 1 hour during angioplasty One infusion
ReCLAIM-2 (2)14 176 adults with dry macular degeneration 40 mg once daily under the skin 48 weeks
ReNEW (3, ongoing)9 313 people with dry macular degeneration 40 mg once daily under the skin 96 weeks
LHON trial (2)15 12 adults with Leber hereditary optic neuropathy 1% eye drops 52 weeks
Kidney artery pilot (2a)16 14 adults having renal artery stenting Infusion at 0.05 mg/kg per hour Before and during the procedure

Doses used in animal studies

Animal studies dosed by body weight, mostly by injection into the abdominal cavity (intraperitoneal):

  • Mice aged 27 months: one 3 mg/kg injection into the abdominal cavity; an 8-day course was also tested, at a dose the abstract does not state.17
  • Female mice aged 26 months: 3 mg/kg/day for 8 weeks.18
  • Mice aged 24 months: 10 mg/kg/day for 2 weeks.19
  • Aged female mice with fatty liver: 3 mg/kg/day.20
  • A Barth syndrome mouse model (TAZ knockdown): 5 mg/kg/day for 6 weeks, which did not persuasively improve heart function.10
  • Rats (fertility studies): up to 20 mg/kg/day under the skin, about 5 times human exposure at 40 mg, without harm to fertility.1

The label compares species by drug exposure, not by dose in mg/kg.1 Animal doses do not convert to human doses.

No dose for research-grade SS-31

No human dose is established for research-grade SS-31. It is made outside the Forzinity approval, and FDA's August 2026 warning letters called SS-31 sold by online sellers an unapproved new drug.1121 Trial doses applied to specific patients under medical supervision and are not instructions for anyone. Peptide dosage basics explains how published doses are reported. For the compound's background, see What is SS-31?; for safety data, see SS-31 side effects.

More on SS-31

  • SS-31 benefits and uses

    What published sources report about SS-31 and its uses, with the evidence level of each finding. No promises.

  • SS-31 side effects

    Side effects of SS-31 as reported in labels, trials and published studies, with links to the full profile. Reviewed by a qualified reviewer.

SS-31 in the store

SS-31 for sale: strengths, stock and shipping are on the product page.

For research use only. Not for human or veterinary use. Read the research use policy.

Frequently asked questions

What is the SS-31 dosage?

Only one SS-31 dosage is established: the Forzinity label dose of 40 mg a day under the skin.1 It applies to Barth syndrome patients who weigh 30 kg or more.1 The prescriber sets it; the label lowers it to 20 mg for adults with severe kidney impairment who are not on dialysis.1 Daily doses of 4 to 60 mg were tested in trials of other diseases, and none became an approved dose.231

Is SS-31 dosed by body weight?

Not on the label. Forzinity uses one fixed dose, 40 mg once daily, for patients who weigh at least 30 kg, lowered only for severe kidney impairment.1 Below 30 kg, safety and effectiveness are not established, and the company has said it plans a 1-month drug-level study in smaller children.14 Some trials did dose by weight: infusions into a vein ran at 0.005 to 0.25 mg/kg per hour.56

How long was SS-31 given in clinical trials?

Courses ranged from one infusion to several years. A heart attack study and one heart failure study gave a single infusion, and a myopathy study gave infusions for 5 days.756 Daily injections ran 4 to 48 weeks in most trials, and the ongoing ReNEW trial runs 96 weeks.839 In the Barth syndrome extension, 8 patients reached 168 weeks and 3 reached 192 weeks.1

Does kidney function change the SS-31 dose?

For Forzinity, yes, in severe impairment. Drug exposure rose by 39%, 75% and 125% in mild, moderate and severe kidney impairment.1 The label lowers the dose to 20 mg once daily for adults with eGFR below 30 mL/min who are not on dialysis.1 It gives no dose for adults on dialysis or for children of 30 kg or more with kidney impairment.1 The drug leaves the body through the kidneys.10

Written by D2C Peptides Editorial Team.

Pending qualified review.

Updated .

Sources

  1. FORZINITY (elamipretide) injection prescribing information: Indications and Usage. DailyMed, U.S. National Library of Medicine (label by Stealth BioTherapeutics Inc., revised 9/2025), 2025.
  2. Effects of Elamipretide on Left Ventricular Function in Patients With Heart Failure With Reduced Ejection Fraction: The PROGRESS-HF Phase 2 Trial (design). Journal of Cardiac Failure (PubMed abstract, PMID 32068002), 2020.
  3. NuPower: Phase 3 trial of elamipretide in primary mitochondrial disease from nuclear DNA mutations (NCT05162768). ClinicalTrials.gov, U.S. National Library of Medicine, 2025.
  4. Stealth BioTherapeutics Provides Commercial Launch Update and Pipeline Progress Across Mitochondrial Disease Portfolio (April 30, 2026). Stealth BioTherapeutics Inc. via PR Newswire, 2026.
  5. Novel Mitochondria-Targeting Peptide in Heart Failure Treatment: A Randomized, Placebo-Controlled Trial of Elamipretide (design). Circulation: Heart Failure (PubMed abstract, PMID 29217757), 2017.
  6. Randomized dose-escalation trial of elamipretide in adults with primary mitochondrial myopathy (MMPOWER): design. Neurology (PubMed abstract, PMID 29500292), 2018.
  7. EMBRACE STEMI study: a Phase 2a trial of intravenous MTP-131 on reperfusion injury (design). European Heart Journal (PubMed abstract, PMID 26586786), 2016.
  8. A randomized crossover trial of elamipretide in adults with primary mitochondrial myopathy (MMPOWER-2): design. Journal of Cachexia, Sarcopenia and Muscle (PubMed abstract, PMID 32096613), 2020.
  9. ReNEW: Phase 3 trial of subcutaneous elamipretide in dry AMD (NCT06373731). ClinicalTrials.gov, U.S. National Library of Medicine, 2026.
  10. FDA Briefing Document, NDA 215244 elamipretide hydrochloride injection, Cardiovascular and Renal Drugs Advisory Committee (pharmacokinetics). U.S. Food and Drug Administration, 2024.
  11. Drugs@FDA: NDA 215244, FORZINITY (elamipretide hydrochloride). U.S. Food and Drug Administration (Drugs@FDA), 2025.
  12. A phase 2/3 randomized clinical trial followed by an open-label extension to evaluate the effectiveness of elamipretide in Barth syndrome (TAZPOWER): methods. Genetics in Medicine (PubMed abstract, PMID 33077895), 2021.
  13. Efficacy and Safety of Elamipretide in Individuals With Primary Mitochondrial Myopathy: The MMPOWER-3 Randomized Clinical Trial (enrollment and outcome). Neurology (PubMed abstract, PMID 37268435), 2023.
  14. ReCLAIM-2: A Randomized Phase II Clinical Trial Evaluating Elamipretide in Age-related Macular Degeneration (methods). Ophthalmology Science (PubMed abstract, PMID 39605874), 2024.
  15. Elamipretide Topical Ophthalmic Solution for the Treatment of Subjects with Leber Hereditary Optic Neuropathy: A Randomized Trial (design and primary result). Ophthalmology (PubMed abstract, PMID 37923251), 2024.
  16. Phase 2a Clinical Trial of Mitochondrial Protection (Elamipretide) During Stent Revascularization in Patients With Atherosclerotic Renal Artery Stenosis. Circulation: Cardiovascular Interventions (PubMed abstract, PMID 28916603), 2017.
  17. Mitochondrial-targeted peptide rapidly improves mitochondrial energetics and skeletal muscle performance in aged mice (dose and energetics). Aging Cell (PubMed abstract, PMID 23692570), 2013.
  18. Improving mitochondrial function with SS-31 reverses age-related redox stress and improves exercise tolerance in aged mice (muscle). Free Radical Biology and Medicine (PubMed abstract, PMID 30597195), 2019.
  19. Treatment with the mitochondrial-targeted antioxidant peptide SS-31 rescues neurovascular coupling responses and cerebrovascular endothelial function in aged mice. Aging Cell (PubMed abstract, PMID 29405550), 2018.
  20. Targeting Mitochondria in MASLD: Comparative Evaluation of MitoQ and SS-31 (Elamipretide) in Aged Female Mice under Nutritional Stress (groups and contrast). Physiological Research (PubMed abstract, PMID 42708867), 2026.
  21. Warning Letter 735067: TXP Innovations LLC dba Tex Peptides (August 24, 2026). U.S. Food and Drug Administration, CDER, 2026.