What are the doses of SS-31 peptide? Clinical Trials & Research Dosing

October 12, 2025 •

4 min read

Elamipretide (SS-31) has been studied in numerous clinical trials and preclinical models, with diverse dosing strategies depending on the condition and route of administration. What are the doses of SS-31 peptide used in this research? Dosages have ranged with many trials exploring specific regimens for conditions like heart failure and primary mitochondrial myopathy.

Quick Summary

SS-31 (elamipretide) is an investigational drug with no standardized FDA-approved dosage for general use, although it has received accelerated approval for Barth Syndrome. Human clinical trials have utilized various doses via intravenous infusion (e.g., 0.01 to 0.25 mg/kg/hour) and subcutaneous injection (e.g., 4 mg, 40 mg daily) for specific durations in research settings.

Key Points

Investigational Status: SS-31 (elamipretide) is an investigational drug with no official, universally standardized dosage for general use, although it has accelerated FDA approval for Barth Syndrome.
Common SubQ Dose in Trials: The most frequently used dosage in late-stage human clinical trials for chronic conditions like mitochondrial myopathy was 40 mg administered once daily via subcutaneous injection.
IV Infusion Range in Trials: Intravenous infusion doses in acute care settings ranged depending on the phase of the trial and the condition being studied.
Preclinical Doses: In animal research, effective doses typically fell within the 0.5 mg/kg to 10 mg/kg range, often administered daily or a few times per week.
Administration Method: SS-31 is primarily administered via subcutaneous injection (for ongoing use) or intravenous infusion (for acute treatment/trials).
Medical Guidance is Crucial: Any use of SS-31 must be done under the strict supervision of a qualified healthcare provider due to its nature as a research compound and the need for appropriate dosing for the approved indication.

Before considering information about SS-31 peptide (elamipretide), it is important to understand that information on medications is for general knowledge only and does not constitute medical advice. Consult with a healthcare provider for any health concerns or before making decisions about treatment.

SS-31, also known by its clinical name elamipretide or brand name FORZINITY™, is a novel mitochondria-targeting peptide that has been extensively studied for its potential to treat diseases linked to mitochondrial dysfunction, such as Barth syndrome and primary mitochondrial myopathy. While it has received accelerated FDA approval for Barth Syndrome, there are currently no universally standardized or FDA-approved doses for general use; all dosages are part of controlled research protocols or expanded access programs under medical supervision.

The doses of SS-31 peptide vary significantly based on the intended use, administration route (intravenous or subcutaneous), and specific patient population studied in clinical trials.

Intravenous (IV) Infusion Dosing in Research

Intravenous administration has primarily been used in early-stage clinical trials (Phase 1 and 2a) and in acute settings, such as during or after a heart attack or renal angioplasty.

Examples of IV dosages used in studies include:

Dose Escalation Studies: In a Phase I/II trial for primary mitochondrial myopathy (MMPOWER), participants received doses over a 2-hour infusion period.
Acute Myocardial Infarction: A Phase 2a trial used a dose for 1 hour, which was reported as safe and well-tolerated.
Renal Artery Stenosis: A study in patients undergoing renal angioplasty administered doses for 3 hours.
Heart Failure: Phase 1 trials for heart failure involved a 4-hour infusion over a wide dose range.

Subcutaneous (SubQ) Injection Dosing in Research

Subcutaneous injections are generally used for longer-term treatment protocols in chronic conditions and late-stage clinical trials. This is the more common route for ongoing use outside of an acute care setting.

Examples of SubQ dosages used in studies include:

Primary Mitochondrial Myopathy & Barth Syndrome: The Phase 3 MMPOWER-3 trial and Phase 2/3 TAZPOWER trials used a consistent dose of 40 mg daily via subcutaneous injection for periods of 12 to 24 weeks.
Heart Failure (HFrEF): A Phase 2 trial randomized patients to receive either a 4 mg or 40 mg daily dose for 28 days.
Age-Related Macular Degeneration: A Phase 2 study is testing daily doses in the range of 40 mg to 60 mg.
Clinical Practice (Off-label/Compounded): Some clinics and research settings utilizing compounded peptides may recommend daily doses for shorter cycles, although these are not FDA-approved protocols.

Comparison of Dosing Regimens in Human Trials

The table below summarizes key dosing regimens used in human clinical trials, highlighting the variations in route and dosage for different indications.


Condition Studied	Route of Administration	Dosage Regimen	Duration
Primary Mitochondrial Myopathy (PMM)	Intravenous (IV) Infusion	Varying mg/kg/hour doses	2 hours
PMM & Barth Syndrome	Subcutaneous (SubQ) Injection	40 mg once daily	12 to 24 weeks
Heart Failure (HFrEF)	Subcutaneous (SubQ) Injection	4 mg or 40 mg once daily	28 days
Acute Myocardial Infarction	Intravenous (IV) Infusion	0.05 mg/kg/hour	1 hour
Renal Artery Stenosis	Intravenous (IV) Infusion	0.05 mg/kg/hour	3 hours
Age-Related Macular Degeneration	Subcutaneous (SubQ) Injection	40 mg to 60 mg once daily	52 weeks

Note: These doses are for investigational purposes and are not approved for general medical use, except as prescribed by a physician for Barth Syndrome.

Preclinical Study Doses

In animal models, dosages are often calculated differently (e.g., mg/kg body weight) and administered via intraperitoneal (i.p.) or subcutaneous routes. Effective doses in rodent studies have typically ranged from 0.5 to 10 mg/kg, with a 5 mg/kg dose being identified as optimal in several neuroprotection models.

Conclusion

The appropriate dosage for the SS-31 peptide (elamipretide) is determined by a physician, particularly as it has received accelerated FDA approval for Barth Syndrome (under the brand name FORZINITY™). The most common and extensively studied long-term dose in late-stage human trials was 40 mg administered daily via subcutaneous injection. For those in an expanded access program or using compounded versions, dosages vary, but it is critical to consult with a qualified healthcare professional, as self-administration from unregulated sources is not advised.

For more detailed information on elamipretide and its development status, you can visit the developer's website.

Important Considerations

No Standardized Guidelines for General Use: Because elamipretide has been largely investigational, there are no standard dosage guidelines for the general public, except as prescribed for Barth Syndrome.
Medical Supervision Required: All use of SS-31 should be strictly supervised by a trained physician within a clinical trial, a legal expanded access program, or for the approved indication.
Administration: The primary routes of administration are IV infusion for acute issues and daily SubQ injections for chronic management.
Adverse Events: The most common reported side effects across trials are mild to moderate injection site reactions (pain, bruising, erythema).

Disclaimer: The information provided here is for educational purposes and is based on published clinical trial data. It is not medical advice. Consult a healthcare professional before making any decisions regarding your health or medication.

Frequently Asked Questions

Yes, elamipretide (SS-31), branded as FORZINITY™, recently received accelerated FDA approval to improve muscle strength in adult and pediatric patients with Barth syndrome. The specific approved dosage is determined by a physician, but clinical trials for this condition typically used a 40 mg daily subcutaneous injection.

SS-31 is typically administered via subcutaneous (SubQ) injection for long-term or chronic use protocols. In clinical trials focusing on acute conditions (like heart attack or kidney injury), it was administered as an intravenous (IV) infusion under controlled medical supervision.

Human clinical trial dosages have varied. Subcutaneous doses were typically 4 mg or 40 mg daily. Intravenous doses ranged depending on the phase of the trial and the condition being studied.

Not always. In a heart failure trial, 4 mg and 40 mg doses showed no significant difference in the primary endpoint (LVESV reduction) compared to placebo. However, in a primary mitochondrial myopathy trial, a dose-dependent increase in the 6-minute walk test distance was observed, with the highest dose showing the most significant effect.

No. SS-31 is a potent peptide that should only be used under the direct supervision of a qualified medical professional, especially since standardized guidelines for general use do not exist. Self-dosing from unregulated sources is strongly discouraged.

SS-31 is generally well-tolerated. The most common side effects reported in clinical trials are mild to moderate reactions at the injection site, such as bruising, pain, or irritation. Dizziness and headaches have also been reported in some studies.

While not officially approved, some research or longevity clinics using compounded SS-31 may suggest protocols like 4 mg or 5 mg daily via subcutaneous injection for cycles of 20 days or longer, aiming for a balance between efficacy and cost-effectiveness. However, these are not FDA-approved protocols, and consultation with a healthcare professional is essential.