LA LABResearch Reference Document
Compound Guide
SS-31 — Elamipretide / Forzinity (MTP-131)
Quick Start
FDA Approved — Narrow Indication
SS-31 / Elamipretide was FDA approved on September 19, 2025 under the brand name Forzinity for Barth syndrome in patients weighing ≥30 kg. This is a rare mitochondrial cardiomyopathy affecting mostly males. All other uses of SS-31 are investigational. Forzinity (280mg/3.5mL; 80mg/mL) is a ready-to-use solution — no reconstitution needed.
What It Is
SS-31 (also known as Elamipretide, MTP-131, or Bendavia) is a cell-permeable, mitochondria-targeting tetrapeptide. It concentrates at the inner mitochondrial membrane by binding cardiolipin — a phospholipid critical for cristae structure and electron transport chain function. It was developed by Stealth BioTherapeutics.
Approved Dosing (Forzinity / Barth syndrome)
40 mg SubQ once daily (patients ≥30 kg). Severe renal impairment (eGFR <30): reduce to 20 mg/day. Forzinity is supplied as a ready-to-use injection — no reconstitution needed. Community research protocols typically use 1–10 mg/day (far below the approved clinical dose).
Regulatory Status
FDA approved (Forzinity) September 19, 2025 for Barth syndrome. All other indications are investigational. Not on WADA prohibited list. Research vials (lyophilised) require reconstitution and are for investigational use only.
Dosing Context
| Context | Dose | Frequency | Source |
|---|---|---|---|
| Forzinity (Barth syndrome) | 40 mg (≥30 kg); 20 mg (eGFR <30) | Once daily SubQ | FDA-approved label |
| TAZPOWER trial | 40 mg/day | Once daily SubQ | Crossover RCT; 12 weeks; primary endpoint missed |
| Community research | 1–10 mg/day | Once daily SubQ | Off-label; not clinically validated |
Supplies & Reconstitution (Research Vials)
Reconstitution Math — 10 mg Vial (3 mL BAC)
| Target Dose | Units (U-100) | Doses / Vial |
|---|---|---|
| 2.5 mg | 75.0 units | 4 |
| 5 mg | 150.0 units | 2 |
| 10 mg | 300.0 units | 1 |
Reconstitute the 10 mg vial with 3.0 mL bacteriostatic water (sold separately) → 3.33 mg/mL. U-100 syringe = 100 units per mL. Swirl gently — do not shake. Refrigerate 2–8°C.
Reconstitution Steps
01
Warm the vial
Allow vial to reach room temperature from freezer (10–15 min) before reconstitution.
02
Swab both stoppers
Alcohol swab both vial tops. Air-dry before inserting needle.
03
Draw BAC water and inject along wall
Draw required BAC water and run slowly down the inside glass wall of the peptide vial. Do not jet onto the powder.
04
Swirl gently until clear
Gently swirl — do not shake or vortex. Solution should be clear and colourless.
05
Refrigerate
Store at 2–8°C for up to 30 days. Protect from light. Do not freeze after reconstitution.
Mechanism of Action
Cardiolipin Binding
SS-31 selectively accumulates at the inner mitochondrial membrane by binding cardiolipin — a unique phospholipid found almost exclusively at IMM. Cardiolipin is critical for cristae curvature and electron transport chain (ETC) complex assembly.
Cristae Stabilisation
By binding cardiolipin, SS-31 stabilises IMM cristae structure. In Barth syndrome, mutant tafazzin causes abnormal cardiolipin remodelling and cristae fragmentation — SS-31 partially compensates for this structural deficit.
ETC Support / ATP Production
Stabilised cristae support optimal assembly and function of ETC Complexes I–IV and ATP synthase (Complex V). Improved ETC efficiency supports ATP production in energy-depleted mitochondria — the primary clinical rationale in Barth syndrome.
ROS Scavenging
Reduces mitochondrial reactive oxygen species (ROS) production by improving ETC electron flow. Excess electron leak to oxygen produces superoxide — SS-31's ETC stabilisation reduces this leak, studied in ischaemia-reperfusion models.
Key Research
| Study | Design | Key Finding |
|---|---|---|
| TAZPOWER (Phase 3) | Crossover RCT; 12 weeks; Barth syndrome; 40 mg/day | Primary endpoint (6-min walk test) missed. 168-week OLE showed functional improvement. |
| HARP trial | Phase 2; heart failure; 40 mg/day 4 weeks | No significant improvement in 6-min walk vs placebo; well tolerated |
| Multiple ischaemia studies | Phase 2; renal ischaemia, AMI | Mostly negative or neutral primary endpoints; well-tolerated safety profile across trials |
| FDA approval (2025) | Barth syndrome; unmet need pathway | Approved September 19, 2025 as Forzinity based on OLE functional improvement data |
Storage
| Form | Temperature | Duration | Notes |
|---|---|---|---|
| Forzinity (ready-to-use) | 2–8°C (refrigerator) | Per label expiry | Do not freeze; protect from light; ready to inject — no reconstitution |
| Research vial (lyophilised) | −20°C (freezer) | Up to 24 months | Protect from light and moisture |
| Reconstituted research vial | 2–8°C (refrigerator) | Up to 30 days | Do not freeze after reconstitution |
Disclaimer
This document is an educational research reference only. SS-31 (Forzinity) is FDA-approved only for Barth syndrome — all other uses are investigational. Research vial doses (1–10 mg/day) are far below the approved clinical dose. By purchasing from LA LAB you confirm you are 18+ and that products are for research purposes only.
Side Effects & Clinical Trial Data
SS-31 is the most heavily trialled compound on this list after the GLP-1s. As elamipretide, Stealth BioTherapeutics took it through Phase 2 and Phase 3 in primary mitochondrial myopathy and Barth syndrome. That means real safety data — and real efficacy results, which you should know before buying it.
| Reported in trials | Detail |
|---|---|
| Injection-site reactions | By far the most common finding — redness, itching, induration. Frequent enough to be the main tolerability issue. |
| Headache | Reported across trials. |
| Nausea, diarrhoea | Reported; generally mild. |
| Dizziness | Reported by a minority. |
The efficacy results were mostly negative
MMPOWER-3, the Phase 3 trial in primary mitochondrial myopathy, did not meet its primary endpoint — elamipretide failed to beat placebo on the six-minute walk test. Barth syndrome results were more mixed and the regulatory path there has been contested. Anyone buying SS-31 for “mitochondrial health” should know that the largest properly-run trial of it was negative for its main measure.
Who Should Avoid SS-31
| Situation | Why |
|---|---|
| Pregnancy or breastfeeding | Avoid. No safety data in pregnancy. |
| Under 18 | Trials in children were in specific diagnosed conditions under supervision, not in healthy adolescents. |
| Active cancer | Not studied. Mitochondrial function is central to tumour metabolism and the direction of effect is unknown. |
| Expecting it to treat a diagnosed mitochondrial disease | Speak to a specialist. This is a condition with real clinical management, and a research peptide is not a substitute. |
Frequently Asked Questions
Does SS-31 work?
For its primary Phase 3 endpoint in mitochondrial myopathy, no — it did not beat placebo. That is the clearest human evidence available. Earlier-phase and Barth syndrome data were more encouraging, which is why development continued.
For its primary Phase 3 endpoint in mitochondrial myopathy, no — it did not beat placebo. That is the clearest human evidence available. Earlier-phase and Barth syndrome data were more encouraging, which is why development continued.
What does it actually do?
It binds cardiolipin, a lipid in the inner mitochondrial membrane, and is thought to stabilise the structures that produce cellular energy. The mechanism is well characterised — better than most compounds here.
It binds cardiolipin, a lipid in the inner mitochondrial membrane, and is thought to stabilise the structures that produce cellular energy. The mechanism is well characterised — better than most compounds here.
Is SS-31 the same as elamipretide?
Yes. Elamipretide is the drug-development name, SS-31 the research name.
Yes. Elamipretide is the drug-development name, SS-31 the research name.
Will I feel anything?
The trials measured walking distance and muscle function over months, not day-to-day sensation. Anyone reporting they felt it immediately is not describing something the trials found.
The trials measured walking distance and muscle function over months, not day-to-day sensation. Anyone reporting they felt it immediately is not describing something the trials found.
How do I know my vial contains what it says?
Check the certificate. Our SS-31 batch tested at 8.44mg against a 10mg label — that report is published under Research → Lab Results, and you should read it before buying.
Check the certificate. Our SS-31 batch tested at 8.44mg against a 10mg label — that report is published under Research → Lab Results, and you should read it before buying.
Can I stack it with MOTS-c or NAD+?
People do, on the theory that they all touch mitochondrial function. No study has tested any combination.
People do, on the theory that they all touch mitochondrial function. No study has tested any combination.
Sources & Research
Szeto HH. First-in-class cardiolipin-protective compound as a therapeutic agent to restore mitochondrial bioenergetics. Br J Pharmacol 2014;171:2029–50.
Karaa A et al. Randomized dose-escalation trial of elamipretide in adults with primary mitochondrial myopathy. Neurology 2018;90:e1212–e1221.
Karaa A et al. A randomized crossover trial of elamipretide in adults with primary mitochondrial myopathy (MMPOWER-2). J Cachexia Sarcopenia Muscle 2020;11:909–918.
MMPOWER-3 — Phase 3 trial in primary mitochondrial myopathy; the primary endpoint (six-minute walk test) was not met.
Regulatory status — not approved by SAHPRA. Its US regulatory history has been contested and it holds no broad approval.
Educational reference only
This document is a research reference, not medical advice and not a treatment plan. SS-31’s Phase 3 trial in mitochondrial myopathy did not meet its primary endpoint, and it is not approved by SAHPRA. Dose decisions belong to you and your prescriber. Independent certificates of analysis for every LA LAB batch are published under Research → Lab Results, with the Janoshik task number and verification key so you can check them yourself.