mitochondria-targeted tetrapeptide · studied for Barth syndrome muscle strength (FDA accelerated approval 2025), mitochondrial myopathy, heart failure and dry AMD trials

SS-31 dosage

SS-31 is elamipretide, approved by the FDA in September 2025 as Forzinity for Barth syndrome at 40 mg subcutaneous once a day. Trials in heart failure and mitochondrial myopathy used similar daily doses. Community use is 5 to 10 mg a day, a fraction of the label dose, in 4 to 8 week blocks. Injection site reactions hit every patient in the pivotal trial, so rotate sites.

By the Peptide Calculations editors · Updated 2026-10-19

40 mg once dailyper day

Basis: FDA label. Forzinity, subcutaneous, patients 30 kg and over; 20 mg daily with severe kidney impairment

How often: once daily, same time each day
When: morning; skip a missed dose, do not double (label)
How long: label: continuous; community: 4 to 8 weeks on, 4 weeks off
Route: subcutaneous, abdomen, rotating sites
Storage: lyophilized: fridge; reconstituted: fridge, use within 4 weeks (commonly reported); Forzinity vials are refrigerated

Dose ranges by source

Range	Per	Basis	Note
40 mg once daily	day	FDA label	Forzinity, subcutaneous, patients 30 kg and over; 20 mg daily with severe kidney impairment
5 mg to 10 mg per day	day	commonly reported	subcutaneous, 4 to 8 weeks; no trial at this dose

SS-31 dose to units chart

50 mg vial + 2 mL bacteriostatic water = 25 mg/mL (250 mcg per unit on a U-100 insulin syringe). 50 mg + 2 mL = 25 mg/mL, so 5 mg = 0.2 mL = 20 units and 10 mg = 40 units. A 10 mg vial + 1 mL is 10 mg/mL: 5 mg = 50 units.

Dose	mL	Units (U-100)	Doses per vial
40 mg	1.6	160	1
50 mg	2	200	1

Different vial or water? Full 50 mg + 2 mL table or set your own numbers below.

Commonly stacked with

MOTS-c 0.5 mg/kg to 5 mg/kg

Side effects

injection site redness (100% in the trial), pain (75%), swelling and itching (67%)
allergic reactions including serious ones (label warning)
headache (reported)
dizziness (reported)

Before you start. The approval is accelerated and the randomized part of the pivotal trial did not beat placebo on its primary endpoints; the FDA requires a confirmatory trial. The label warns of hypersensitivity reactions. The community dose has no efficacy data at all. Not medical advice. Talk to a clinician and start low.

SS-31 dosage questions

SS-31 dosage?

The FDA label for Forzinity is 40 mg subcutaneous once a day for Barth syndrome. Community users take 5 to 10 mg a day for 4 to 8 weeks, which has no trial behind it. If the point is mitochondrial support in a healthy person, nobody has shown the low dose does anything.

How many units of SS-31 is 5 mg?

With 50 mg in 2 mL (25 mg/mL) 5 mg is 20 units and 10 mg is 40 units. With a 10 mg vial in 1 mL, 5 mg is 50 units.

Is SS-31 FDA approved?

Yes, as Forzinity (elamipretide) since September 2025, under accelerated approval for Barth syndrome only. The randomized part of the trial did not beat placebo on its main endpoints; approval rested on muscle strength gains in the open-label extension.

What are the side effects of SS-31?

Injection site reactions, mainly. In the pivotal trial every patient had redness, three quarters had pain and two thirds had swelling or itching. The label also warns of allergic reactions, some needing emergency care.

Sources

Brands we recommend for SS-31. We are independent and have no affiliation with any brand: no affiliate links, no referral codes, no paid placements. These are the suppliers whose testing and certificates hold up when we check them.

Licensed Peptides two accredited labs on every lot, certificates public, card and Apple Pay checkout
Core Peptides long track record, public certificates, wide catalog
Ascension Peptides public third-party testing, clear pricing

This page is an educational summary of published labels, trials and commonly reported use. It is not medical advice and does not replace a clinician.