SS-31 Quick Start
SS-31 is a four-amino-acid peptide with an alternating aromatic-cationic structure that causes it to accumulate in the inner mitochondrial membrane at concentrations far above plasma. There it binds cardiolipin, a phospholipid essential to the structure of the electron-transport chain. Unlike most compounds in this catalog it has been through named clinical trials as elamipretide, which gives it an unusually concrete evidence base.
This guide is an educational research reference. It does not diagnose, treat, or prescribe, and is not medical advice. Consult a licensed clinician before considering any compound.
SS-31 Dosing Protocol
SS-31 doses sit in the milligram range, which makes the reconstitution volume a practical decision — a 5 mg dose is a substantial fraction of the vial. Published trials of elamipretide used 40 mg daily subcutaneously in some indications; the research-planning bands below are considerably more conservative and are not personal dosing recommendations.
Injection — Subcutaneous
| Band | Per dose | Frequency |
|---|---|---|
| Low | 2.5 mg | Once daily |
| Standard | 5 mg | Once daily |
| High | 10 mg | Once daily |
SS-31 Reconstitution Guide
SS-31 ships as a lyophilized powder. Because the doses are milligram-scale, a smaller reconstitution volume keeps the draw within one syringe.
Injection
| BAC | Conc. | 5 mg |
|---|---|---|
| 1 mL | 10 mg/mL | 0.5 mL · 50 u |
| 2 mL | 5 mg/mL | 1.0 mL · 100 u |
Units are U-100 insulin-syringe units. At 2 mL a 5 mg dose fills an entire 100-unit syringe — the 1 mL reconstitution is usually the more practical choice.
Reconstitution steps
- Inspect the vial. Confirm the label, expected milligram amount, and that the powder looks dry and intact.
- Wipe the stoppers. Use an alcohol swab on both the bacteriostatic water and peptide vial stoppers.
- Draw the chosen volume. 1 mL (or 2 mL for a more dilute solution) into the vial — this is the number that sets every concentration figure above.
- Inject down the wall. Release the water slowly down the inside wall, not directly onto the powder.
- Swirl, do not shake. Roll gently until dissolved. Shaking foams and can damage the peptide.
- Verify clarity. Solution should be clear and colorless. Discard if cloudy or particulate.
- Label and refrigerate. Note the date and volume added on the vial, then store at 2–8 °C. Do not freeze the reconstituted solution.
See the bacteriostatic water guide for diluent handling, or the reconstitution calculator to work any other volume.
How SS-31 Works
SS-31 concentrates in the inner mitochondrial membrane and binds cardiolipin, the phospholipid that organises the protein complexes of the electron-transport chain. By stabilising cardiolipin it is reported to improve the structural integrity of cristae, increase ATP production efficiency, and reduce electron leak — the source of mitochondrial reactive oxygen species. The mechanism is structural rather than antioxidant in the conventional radical-scavenging sense.
Cardiolipin binding
Stabilises the phospholipid that organises electron-transport-chain complexes.
Cristae structure
Reported to preserve inner-membrane architecture in damaged mitochondria.
Reduced electron leak
Less leak means fewer reactive oxygen species generated at source.
Open question
Trial results have been mixed — mechanism plausibility has not consistently translated into clinical endpoints.
Who Should Avoid SS-31
Human exposure data comes largely from supervised trial settings, which does not transfer to unsupervised use of research-grade material.
Pregnancy & lactation
No published human reproductive safety data.
Active or prior cancer
Mitochondrial function is central to cell survival; effects on tumour metabolism are uncharacterised.
Anyone seeking a treatment
Elamipretide is investigational; trial outcomes have been mixed and it is not an approved therapy.
Unmonitored settings
Published exposure is overwhelmingly from supervised trials with structured monitoring.
SS-31 Side Effects & Safety
Injection-site reactions
The most frequently reported adverse event in the trial programme, and the dose-limiting issue in some studies.
General tolerability
Otherwise reported as reasonably well tolerated across trials at supervised doses.
Unknown long-term profile
Chronic-use data outside trial settings does not exist.
Quality-control risk
Verify identity and purity against a Certificate of Analysis.
SS-31 Evidence Context
Barth syndrome trials
Studied in this rare cardiolipin-remodelling disorder, the most mechanistically direct indication.
Mitochondrial myopathy
Trialled in primary mitochondrial myopathy with mixed endpoint results.
Ophthalmic and cardiac work
Investigated in dry AMD and heart-failure settings.
Open question
Several trials missed primary endpoints; the gap between mechanism and outcome is the honest summary.
Storage & Handling
| State | Storage | Notes |
|---|---|---|
| Lyophilized (powder) | −20 °C, protected from light | More stable than reconstituted solution. |
| Reconstituted (liquid) | 2–8 °C short-term | −20 °C for longer per the listing. |
| Appearance | Clear, colorless | Discard cloudy or particulate solutions. |
SS-31 vs MOTS-c vs NAD+
| Feature | SS-31 | MOTS-c | NAD+ |
|---|---|---|---|
| Class | Targeting tetrapeptide | Mitochondrial-derived peptide | Coenzyme |
| Mechanism | Cardiolipin / membrane structure | Metabolic signalling | Redox cofactor substrate |
| Evidence tier | Named clinical trials | Preclinical | Preclinical / early |
| Page | This page | MOTS-c | NAD+ |
Frequently Asked Questions
What is SS-31?
A mitochondria-targeting tetrapeptide, also called elamipretide or MTP-131, that concentrates in the inner mitochondrial membrane and binds cardiolipin.
How is it dosed?
Research-planning bands sit at 2.5–10 mg once daily. At 10 mg/mL, 5 mg is 50 units on a U-100 syringe. Note that published trials used considerably higher doses.
How many doses in a vial?
At the 5 mg standard band, two. This is a milligram-range compound in a 10 mg vial.
Is it an antioxidant?
Not in the conventional radical-scavenging sense. It acts structurally — stabilising cardiolipin reduces electron leak, so fewer reactive oxygen species are generated in the first place.
Has it worked in trials?
Results have been mixed. It has completed named trials in Barth syndrome, mitochondrial myopathy and ophthalmic indications, with several missing primary endpoints.
Is this page medical advice?
No. It is an educational research reference and does not diagnose, treat, or prescribe. Consult a licensed clinician before considering any compound.
SS-31 Formats & Sourcing
SS-31 is supplied as a lyophilized powder in a single 10 mg vial. There is no pre-reconstituted pen or spray format. Batch-specific Certificates of Analysis are issued per lot.
| Format | Supplied as |
|---|---|
| Vial | 10 mg lyophilized powder |
Strengths are listed as sold; confirm against the product page and the batch COA before calculating anything.
Reference material for this protocol, with batch COA:
View SS-31 on Spyro Peptides →References
- Szeto HH. First-in-class cardiolipin-protective compound as a therapeutic agent. Br J Pharmacol (2014).
- Birk AV, et al. The mitochondrial-targeted compound SS-31 re-energizes ischemic mitochondria. J Am Soc Nephrol (2013).
- Reid Thompson W, et al. A phase 2/3 randomized clinical trial of elamipretide for Barth syndrome. Genet Med (2021).
- Karaa A, et al. Randomized dose-escalation trial of elamipretide in primary mitochondrial myopathy. Neurology (2018).