SS-31 Guide

SS-31 at a glance

What it is

A synthetic mitochondria-targeting tetrapeptide (D-Arg-dimethylTyr-Lys-Phe-NH2), also known as Elamipretide, Bendavia, and MTP-131; the FDA-approved product is branded Forzinity

Approved for

FDA-approved (September 2025, as elamipretide HCl, brand name Forzinity) for Barth syndrome only; investigational for other mitochondrial conditions

Commonly reported range

5-10 mg once daily is the commonly reported example range; clinical trials used up to 40 mg/day subcutaneously (examples, not a recommendation)

Route reported

Subcutaneous injection (clinical trials also used intravenous infusion)

Reported frequency

Once daily, typically at a consistent time

Reported cycle

8-12 weeks commonly reported; limited human data beyond 12 weeks in non-clinical settings

Plasma half-life

Approximately 2 hours after subcutaneous dosing (Cmax at 1-2 hours)

Regulatory status

FDA-approved for Barth syndrome only; not approved for anti-aging, athletic, or general mitochondrial use; research-only outside that indication

Reported ranges from research/community — examples, not recommendations.

What it is / mechanism

SS-31 is an aromatic-cationic tetrapeptide that concentrates in the inner mitochondrial membrane, where it selectively binds cardiolipin, an anionic phospholipid unique to that membrane. By associating with cardiolipin, it is reported in research to help stabilize the folded cristae architecture that houses the electron transport chain. This interaction is described in studies as supporting more efficient electron transport and ATP production while reducing the leakage of reactive oxygen species. Its alternating cationic and aromatic residues allow it to accumulate in mitochondria through electrostatic attraction without depending on membrane potential. These are described mechanisms from laboratory and preclinical research, not guaranteed effects in any individual.

Researched effects

In research settings, SS-31 has been studied for its reported effects on mitochondrial function, including cardiolipin stabilization, improved bioenergetic efficiency, and reduced oxidative stress. In the MMPOWER-3 phase 3 trial in primary mitochondrial myopathy, subcutaneous elamipretide did not meet its co-primary endpoints, and clinical benefit across mitochondrial conditions remains mixed; the strongest regulatory signal was in Barth syndrome. Community and preclinical reports also discuss interest in cardiac, renal, muscle, and age-related mitochondrial contexts. These are research findings and reported observations, not guaranteed outcomes, and much of the non-Barth data is investigational or preclinical.

Dosage — reported ranges (overview)

The figures below are examples of what is reported in clinical literature and research communities, not a recommendation to dose. Clinical trials in primary mitochondrial myopathy and heart failure commonly used 40 mg/day subcutaneously (or weight-based intravenous infusion at 0.01-0.25 mg/kg). Research-community discussions more often reference fixed subcutaneous examples of 5-10 mg once daily, sometimes titrated upward. Reported frequency is once daily at a consistent time, and reported cycles are commonly 8-12 weeks. None of this constitutes a personal dose or medical guidance.

The full step-by-step protocol examples, titration, and printable protocol sheet are planned for a future paid Protocol Playbook module.

Reconstitution — bac-water math

SS-31 is dosed in milligrams, so reconstitution is a concentration calculation: concentration (mg/mL) = total peptide (mg) divided by the volume of bacteriostatic water added (mL). On a U-100 insulin syringe, 1 mL equals 100 units, so units drawn = (desired mg / concentration in mg/mL) x 100. As a worked example, a 10 mg vial reconstituted with 2 mL of bacteriostatic water gives 5 mg/mL; a 5 mg example dose is then 1.0 mL, which is 100 units on a U-100 syringe. This is concentration math only, not a personal dose.

This is concentration math, not a dose recommendation.

Injection / administration basics

In reported protocols and clinical trials, SS-31 is given as a subcutaneous injection, typically into the abdominal fat a couple of inches from the navel or into the thigh, using a small insulin syringe. Common practice described in the community includes rotating injection sites to reduce irritation, injecting at a consistent time each day, and swabbing the site with alcohol beforehand. Because example mg doses are relatively large, a single dose may use a substantial fraction of a vial or more than one syringe draw. This is a general description of reported technique, not medical instruction.

Half-life & frequency rationale

The plasma half-life of elamipretide after subcutaneous administration is reported at approximately 2 hours, with peak plasma concentration (Cmax) typically reached 1 to 2 hours post-injection. This short half-life is one reason clinical dosing has generally been once daily. Reported pharmacokinetics come from clinical trial data.

Stacking — overview

In research and community discussion, SS-31 is often described as being paired with other agents that target mitochondrial function or recovery, on the rationale of combining structural mitochondrial support with metabolic cofactors or tissue-repair peptides. The pairings below are examples reported in the community, not endorsements or recommendations, and combining research compounds increases uncertainty around safety and interactions.

Storage & handling

• Lyophilized (freeze-dried) SS-31 vials are reported to be stored frozen at around -20 degrees C and protected from light, remaining stable long-term until reconstituted.
• Once reconstituted with bacteriostatic water, SS-31 is reported to be kept refrigerated at 2-8 degrees C, protected from light, and used within roughly 28 days.

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