SS-31 / Elamipretide

The split that makes this record

Elamipretide is approved. It is approved at 40 mg per day, subcutaneously, to improve muscle strength in adults and children with Barth syndrome weighing at least 30 kg. Barth syndrome affects roughly 150 people in the United States.

The dose sold and discussed as SS-31 for longevity and mitochondrial support is 1 to 10 mg per day, for indications with no human evidence at all.

Those are not the same drug regimen. A four-to-fortyfold difference in dose, in a different population, for a different endpoint, does not inherit an approval. The word "FDA-approved" attached to a 2 mg longevity protocol is doing work it has not earned.

What it actually does

Cardiolipin is a phospholipid found almost nowhere except the inner mitochondrial membrane. It holds the shape of the cristae, the deep folds where the electron transport chain lives, and it physically anchors several respiratory complexes. Barth syndrome is a genetic disorder of cardiolipin remodelling: the lipid is made, then fails to mature correctly, and mitochondrial structure degrades as a result.

Elamipretide binds reversibly to cardiolipin and stabilises that architecture. It is a structural intervention on a specific lipid, which is exactly why the approved indication is a specific disease of that lipid.

Whether stabilising cardiolipin does anything measurable in a healthy 45-year-old with ordinary tiredness is an open question that nobody has run a trial on.

The approval, and a date conflict we do not hide

FDA granted accelerated approval to Forzinity, elamipretide hydrochloride injection, as the first approved therapy for any mitochondrial disease. Accelerated approval means the evidence base is a surrogate endpoint with confirmatory work still owed; it is a real approval with a real asterisk.

On the date, sources disagree. The United Mitochondrial Disease Foundation states 19 September 2025. Other reporting states 26 September 2025. We report both rather than picking one and looking confident.

The formulation detail worth knowing

Each 0.5 mL dose of the approved product contains 40 mg of elamipretide (46.8 mg as the hydrochloride salt), 10 mg of benzyl alcohol as a preservative, and 2.07 mg of monobasic sodium phosphate. It ships in single-patient-use 3.5 mL vials, ready to use.

This is the first compound in the library that contains benzyl alcohol, rather than one we keep away from it as a cautious choice. If you carry a benzyl alcohol sensitivity, that is a direct flag on the approved product, not on the research powder, which arrives dry.

Dosing details from the label

40 mg subcutaneously once daily at 30 kg and above. Reduce to 20 mg daily if eGFR is below 30 mL/min and the patient is not on dialysis. Renal dose adjustment on a peptide is unusual and worth noting: it means clearance depends on kidney function in a way that matters clinically.

The research-vial presets

Two reconstitution pairings circulate for research-grade powder: 10 mg in 1.0 mL of bacteriostatic water gives 10 mg/mL, and 50 mg in 2.5 mL gives 20 mg/mL. Both are on this page because people use them, and both carry no beyond-use window because no source states one. They are not the approved product, which arrives as a solution and is never reconstituted.

Reported effects

Injection-site reactions, early headache, dizziness, mild nausea, fatigue. Half-life could not be located in any source we hold, so it is null rather than estimated.

The honest summary

This is the cleanest example in the library of an approval being borrowed. The drug is real, the mechanism is specific and well characterised, the approval is genuine, and none of it says anything about what 2 mg a day does to a healthy person's energy levels, because that question has never been asked in a trial.