Calculator for SS-31 (Elamipretide / Bendavia / MTP-131) reconstitution and per-administration dosing maths. SS-31 is a four-amino-acid cell-penetrating peptide that binds cardiolipin on the inner mitochondrial membrane.
For research and educational purposes only. This calculator performs volumetric mathematics on the values you enter; it does not recommend doses or provide medical advice.
Dose calculator
Standard research pen format: 3 mL total volume, 300 clicks per pen. That’s fixed — so the only thing that changes is how many mg are in your specific pen. mg per click = your pen’s mg ÷ 300.
Vial mode: most research peptide vials are 3 mL borosilicate glass (industry standard — about 99% of compounds ship in this size). Larger compounds like NAD+ or high-mg GHK-Cu sometimes come in 5–10 mL vials. The bacteriostatic water you add must fit inside your physical vial — for a standard 3 mL vial, that’s usually 1–3 mL of BAC water. Tell us the vial’s peptide content (in mg), the BAC water you added, and your target dose — we work out the concentration, the volume to draw, and the syringe units on a U-100 insulin syringe.
Research and educational purposes only. Not medical advice. Not for human consumption. This calculator performs volumetric mathematics on the values you enter; it does not recommend doses. Compounds listed are not licensed as medicines for human use unless stated otherwise.
About SS-31 (Elamipretide)
SS-31 — also called Elamipretide, Bendavia, or MTP-131 — is a synthetic four-amino-acid cell-penetrating peptide originally developed by Stealth BioTherapeutics. Its sequence is D-Arg-2′,6′-dimethyltyrosine-Lys-Phe-NH2. It crosses the plasma membrane, enters mitochondria, and binds directly to cardiolipin on the inner mitochondrial membrane.
In September 2025 the US FDA granted accelerated approval to Elamipretide (brand name Forzinity) as the first treatment for Barth syndrome in patients weighing at least 30 kg. This makes it the first mitochondria-targeted therapeutic ever approved. The compound is not licensed as a medicine in the UK or EU and is supplied here strictly as a research-grade compound for laboratory study.
How SS-31 works (mechanism)
Cardiolipin is a phospholipid concentrated in the inner mitochondrial membrane where it organises the cristae (the folded membrane structure that houses the electron-transport chain). Published research literature reports that SS-31 binds cardiolipin selectively and is thought to:
- Stabilise cristae structure under oxidative stress
- Reduce production of reactive oxygen species at electron-transport-chain complexes
- Improve ATP output in cells with impaired mitochondrial function
- Preserve mitochondrial membrane potential during ischaemia-reperfusion stress
This mechanism distinguishes SS-31 from upstream mitochondrial peptides such as MOTS-c, which is encoded within mitochondrial DNA itself and acts as a signalling molecule rather than a membrane-binder.
SS-31 in published research literature
Research literature describes investigation of SS-31 / Elamipretide in:
- Barth syndrome — the indication for which Forzinity received FDA accelerated approval (Sept 2025)
- Heart failure with reduced ejection fraction — earlier trials reported approximately 10–15% improvement in peak VO2 after four weeks of intravenous administration
- Primary mitochondrial myopathy — multiple Phase 2/3 trials
- Dry age-related macular degeneration — investigated for retinal mitochondrial protection
- Sarcopenia and age-related mitochondrial decline — pre-clinical models
These reports are cited for completeness of the research-literature picture and do not constitute a recommendation, claim, or assertion about effect in any individual.
Typical research formats
| Format | BAC water | Concentration | Volume to draw | For |
|---|---|---|---|---|
| 50 mg vial (most common) | 2 mL BAC water | 25 mg/mL | 0.20 mL (20 units U-100) | for a 5 mg administration |
| 50 mg vial | 2 mL BAC water | 25 mg/mL | 0.40 mL (40 units U-100) | for a 10 mg administration |
| 100 mg vial | 2 mL BAC water | 50 mg/mL | 0.10 mL (10 units U-100) | for a 5 mg administration |
Pen-style prefilled formats are uncommon for SS-31 — research-grade supply is almost always lyophilised vial. Clinical-trial administration in heart-failure studies used intravenous infusion rather than subcutaneous injection; subcutaneous administration is what the research-grade powder vial format is set up for.
SS-31 doses observed in research literature
Published research-literature dose ranges for SS-31 / Elamipretide vary by indication and administration route:
- Subcutaneous research dose: reports cite 0.1–2 mg/kg per day; for a 70 kg subject this is approximately 7–140 mg/day
- Clinical-trial intravenous dose: 0.01–0.25 mg/kg/hour as a four-hour infusion
- Commonly reported per-administration research dose: 5–10 mg per day, subcutaneous
These figures are reported here for completeness of the research-literature picture and do not constitute a dosage recommendation.
Half-life and frequency
Reported plasma half-life of SS-31 in published research is approximately 2–4 hours. However, cellular retention is materially longer because the peptide accumulates in mitochondrial inner membranes — functional duration commonly exceeds the pharmacokinetic half-life. Research administration is most often described as a single daily subcutaneous administration.
Storage and shelf life
Lyophilised powder: refrigerated 2–8 °C; long-term storage at −20 °C extends shelf life. Reconstituted with bacteriostatic water: approximately 28 days refrigerated. Protect from light. Do not freeze the reconstituted solution.
Side-effect notes from clinical trials
In Forzinity clinical trials, the most commonly reported adverse events were injection-site reactions (erythema, induration), headache, dizziness and gastrointestinal symptoms. Serious adverse events were rare in the approval-supporting studies. As with all subcutaneous research peptides, injection-site rotation and sterile technique are central to reducing local reactions.
Frequently asked questions
What does SS-31 / Elamipretide do?
Published research literature reports that SS-31 binds cardiolipin in the inner mitochondrial membrane, stabilising cristae structure and reducing reactive-oxygen-species production. It is the first mitochondria-targeted therapeutic to gain regulatory approval (Forzinity, FDA Sept 2025, for Barth syndrome).
What is the typical SS-31 research dose?
Published research protocols commonly describe 5–10 mg per administration, subcutaneous, once daily. Clinical-trial dosing ranges from 0.01–0.25 mg/kg/hour intravenously to 0.1–2 mg/kg/day subcutaneously, depending on indication.
How do I reconstitute a 50 mg vial of SS-31?
A common approach uses 2 mL of bacteriostatic water, giving a 25 mg/mL concentration. For a 5 mg target dose, draw 0.20 mL — 20 units on a U-100 insulin syringe. The calculator above will redo the maths for any vial size and target dose you enter.
Is SS-31 / Elamipretide legal in the UK?
Elamipretide is not licensed as a medicine in the UK or the EU. It is unscheduled under the UK Misuse of Drugs Act 1971 and is supplied as a research-grade compound for laboratory study. The compound’s only approved use anywhere is the September 2025 FDA accelerated approval of Forzinity for Barth syndrome in the United States, in patients weighing 30 kg or more.
SS-31 vs MOTS-c — what’s the difference?
Both target mitochondria but via completely different mechanisms. SS-31 is a synthetic tetrapeptide that binds cardiolipin on the inner mitochondrial membrane to stabilise cristae. MOTS-c is a 16-amino-acid peptide encoded within mitochondrial DNA itself and acts as a metabolic-signalling molecule. SS-31 is membrane-active; MOTS-c is signalling-active.
How does SS-31 compare to NAD+ supplementation?
NAD+ is a coenzyme central to mitochondrial energy production. SS-31 is a structural stabiliser of the membrane on which that energy production happens. Different layers of the same mitochondrial-function research stack; published literature investigates them separately rather than as a combined protocol.
Related compounds
- MOTS-c — mitochondrial-DNA-encoded signalling peptide
- NAD+ — mitochondrial coenzyme, longevity research
- 5-amino-1-MQ — NNMT inhibitor, mitochondrial-energy research
- FOXO4-DRI — senolytic research peptide
Where to source research-grade SS-31
For UK readers researching SS-31 / Elamipretide, our partner supplier stocks research-grade preparations. Use code STACK10 for 10% off your first order. We do not sell peptides ourselves and are not responsible for any third-party supplier’s product quality, regulatory compliance, or customer service.
Compliance: Stackcalc.co.uk provides calculator tools and information for research and educational purposes only. We do not sell, supply, or recommend peptides, nootropics, or any other compounds. SS-31 / Elamipretide is not licensed as a medicine in the UK or EU. Content on this site does not constitute medical advice. Always consult a qualified healthcare professional. Not for human consumption.