Restored cristae architecture and respiratory function [1][2]
Demonstrated across cell and animal models of mitochondrial dysfunction, ischaemia-reperfusion and ageing, with improved supercomplex assembly and ATP production.
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PrecisePep/Peptide Library/SS-31
Mitochondrial & Bioenergetic
Elamipretide · MTP-131 · Bendavia · D-Arg-Dmt-Lys-Phe-NH₂
A cardiolipin-binding tetrapeptide that concentrates thousands-fold inside mitochondria and restores cristae architecture — the most clinically advanced mitochondrial-targeted drug candidate that exists.
SS-31 is a genuine pharmacological curiosity. It was discovered by accident — Szeto and Schiller were working on opioid analogues when they found a peptide that concentrated in mitochondria to a remarkable degree. The structural motif responsible is an alternating aromatic-cationic sequence that allows the peptide to partition into the inner mitochondrial membrane independent of membrane potential, reaching intramitochondrial concentrations one to three orders of magnitude above plasma.
What it does there is bind cardiolipin — the signature phospholipid of the inner membrane, essential for cristae curvature and for the assembly of respiratory-chain supercomplexes. Cardiolipin is peroxidation-prone, and its damage is a common final pathway in mitochondrial dysfunction. SS-31 binds it, stabilises cristae architecture, improves electron-transport efficiency and reduces electron leak — meaning less reactive oxygen species produced at source rather than scavenged afterwards.[1][2]
Under the name elamipretide it has been through an extensive clinical programme: primary mitochondrial myopathy, Barth syndrome, heart failure, dry age-related macular degeneration and ischaemia-reperfusion. Results have been mixed — some trials missing primary endpoints, others positive, and the Barth syndrome programme progressing furthest toward regulatory consideration.[3] That mixed record is more informative than any grey-market claim on this page.
Elamipretide has failed primary endpoints in some indications and succeeded in others. That is what a real drug development programme looks like, and it is a far better guide to what this molecule does than the uniformly positive framing it receives in community protocols. A compound that works in inherited cardiolipin-remodelling disease may do nothing measurable in a healthy 45-year-old.
Cardiolipin binding. The core mechanism. Cardiolipin is the inner-membrane phospholipid that shapes cristae and organises respiratory supercomplexes. SS-31 binds it selectively through electrostatic and hydrophobic interaction, modulating membrane surface electrostatics.[2]
Cristae stabilisation. By stabilising cardiolipin-dependent curvature, SS-31 restores cristae architecture in damaged or aged mitochondria. Cristae shape is not cosmetic — respiratory efficiency depends directly on it.
Improved electron transport and ATP output. Better-organised supercomplexes leak fewer electrons and produce more ATP per unit substrate. This is why the antioxidant effect is described as upstream: fewer ROS are generated rather than more being mopped up.
Adenine nucleotide translocator function. Work in aged mitochondria reports improved ADP sensitivity through increased uptake via the ANT — a specific mechanistic finding relevant to age-related bioenergetic decline.[4]
Membrane-potential independence. Unlike triphenylphosphonium-based mitochondrial targeting, SS-31 does not require an intact membrane potential to accumulate — so it reaches the damaged mitochondria that need it most.
Effects that have been reported. A study-tier entry means a result was published — not that the effect is established, reproducible, or transferable from a rodent to a person.
Highest confidenceReported in peer-reviewed literature, registered clinical trials, or regulatory filings. Note the model: much peptide literature is in vitro or rodent work, not human trial data.
Demonstrated across cell and animal models of mitochondrial dysfunction, ischaemia-reperfusion and ageing, with improved supercomplex assembly and ATP production.
Reduced electron leak rather than downstream radical scavenging — mechanistically distinct from conventional antioxidants and a more defensible intervention point.
The mitochondria-targeted peptide improved cardiac and skeletal muscle function during ageing in animal models — notably without detectable change in epigenetic or transcriptomic age measures.
SS-31 ameliorates injury across multiple kidney disease models, one of the better-developed pre-clinical areas for the compound.
Demonstrated improvement in adenine nucleotide translocator-mediated ADP uptake in aged mitochondria — a specific, measurable bioenergetic effect.
Elamipretide has been evaluated in primary mitochondrial myopathy, Barth syndrome, heart failure with preserved ejection fraction, and dry AMD. Results are mixed: some primary endpoints missed, some positive signals, with the Barth syndrome programme advancing furthest.
Unproven — inference onlyExtrapolated from a known mechanism, receptor profile, or adjacent compound class. Biologically plausible but not directly demonstrated for this compound in this context.
The community use case. Mitochondrial function does decline with age and SS-31 does improve it in aged animal tissue — but no trial has assessed healthy human adults, and the ageing-model work explicitly reported functional improvement without change in biological-age markers.
Mitochondrial dysfunction is a leading hypothesis in these syndromes, and the reasoning is plausible. It is also a hypothesis about a poorly characterised condition, tested with an unapproved drug and no diagnostic confirmation of the presumed mechanism.
Follows from improved ATP output. The primary mitochondrial myopathy trials — where an exercise-capacity effect would be easiest to detect — produced mixed results, which argues for caution about the healthy-adult case.
Mitochondrial dysfunction is implicated in neurodegeneration and pre-clinical neuro work exists. No human neuro outcome data.
Extensive pre-clinical cardiac work; the heart failure clinical programme did not deliver a clean positive result.
Uncontrolled reportsAggregated from research-community logs, forums, vendor literature and self-reported experience. Uncontrolled, unverified, subject to placebo, polypharmacy and product-purity confounds. Lowest evidentiary weight.
The characteristic community report, and the one reproduced in circulating protocols: early spikes of energy followed by exhaustion, converting over weeks into steady energy without the crash. Uncontrolled and unmeasured, but strikingly consistent in how it is described.
Frequently reported, particularly by users with fatigue complaints.
Reported and attributed to neuronal energy availability.
SS-31 is among the most expensive research peptides in circulation, which caps both dose and duration in practice and shapes what community protocols look like.
Reported by users without a fatigue complaint — consistent with the idea that restoring impaired function is easier than improving normal function.
Adverse effects, contraindications and unknowns. The grey-market tier is where under-reporting is worst: uncontrolled use produces no systematic safety surveillance at all, so absence of a reported harm is not evidence of safety.
Highest confidenceReported in peer-reviewed literature, registered clinical trials, or regulatory filings. Note the model: much peptide literature is in vitro or rodent work, not human trial data.
Across the elamipretide clinical programme, injection-site erythema, induration and pruritus were the most common adverse events with daily subcutaneous administration.
No major systemic safety signal emerged across the clinical programme at studied doses and durations.
Missed primary endpoints in several indications are not a safety issue but they are the most important trial result to carry into any interpretation of community claims.
Unproven — inference onlyExtrapolated from a known mechanism, receptor profile, or adjacent compound class. Biologically plausible but not directly demonstrated for this compound in this context.
Mitochondrial ROS are signalling molecules, not only damage. Mitohormesis — the principle that transient mitochondrial stress drives adaptive benefit, including much of the adaptation to exercise — means chronically suppressing ROS could theoretically blunt training adaptation.
Damaged mitochondria are normally flagged for degradation. A drug that restores function in damaged organelles could in principle preserve ones that should have been cleared.
A direct extension of the mitohormesis argument, and the most practically relevant unknown for the athletic population using it.
Trials in rare disease populations over defined periods do not characterise years of use in healthy adults.
Uncontrolled reportsAggregated from research-community logs, forums, vendor literature and self-reported experience. Uncontrolled, unverified, subject to placebo, polypharmacy and product-purity confounds. Lowest evidentiary weight.
Consistent with trial findings and the most common community complaint.
Described in circulating protocols as an expected early phase that resolves as "repair occurs". That framing is narrative rather than mechanism, but the pattern is consistently reported.
Occasionally reported at the start of a loading phase.
Reported by some users, hence the convention of morning dosing.
Figures below are documented, not recommended. Study ranges come from published protocols in the stated model; grey-market ranges are what the research community reports using and carry no safety validation of any kind.
Highest confidenceReported in peer-reviewed literature, registered clinical trials, or regulatory filings. Note the model: much peptide literature is in vitro or rodent work, not human trial data.
The elamipretide clinical programme has predominantly used 40 mg once-daily subcutaneous administration in primary mitochondrial myopathy and Barth syndrome, with intravenous dosing in acute cardiac settings.
This is the single most important number on this page. Clinical efficacy — where it was found at all — was found at 40 mg daily. Community protocols use 5 mg. No dose-response data supports the lower figure.
| Setting | Dose | Route | Outcome |
|---|---|---|---|
| Primary mitochondrial myopathy | 40 mg daily | Subcutaneous | Mixed; primary endpoints not consistently met |
| Barth syndrome | 40 mg daily | Subcutaneous | Programme advanced furthest toward regulatory review |
| Heart failure / IR injury | Trial-defined | IV / SC | Mixed |
Unproven — inference onlyExtrapolated from a known mechanism, receptor profile, or adjacent compound class. Biologically plausible but not directly demonstrated for this compound in this context.
Daily administration to restore function, then reduced frequency to hold it. The structure is coherent; the specific amounts are not derived from data.
Aligns with the reported activating effect and avoids sleep disruption. Practical rather than pharmacological.
Either the community dose is sub-therapeutic and the reported effects are placebo, or the trial dose was higher than necessary for the effects users are chasing. Nothing published distinguishes these.
Uncontrolled reportsAggregated from research-community logs, forums, vendor literature and self-reported experience. Uncontrolled, unverified, subject to placebo, polypharmacy and product-purity confounds. Lowest evidentiary weight.
The schedule in the Gold Standard protocol: 5 mg daily for one vial (roughly 10 days), then 5 mg two to three times weekly for eight weeks, then four weeks off, cycling on and off.
The most common ongoing community dose.
Reported by users with the budget for it, still a quarter of the trial dose.
The circulating logic is structural repair first (SS-31), then functional stimulation (MOTS-c) — repair the machinery before demanding output from it.
| Phase | Dose | Frequency | Duration |
|---|---|---|---|
| Initial repair | 5 mg | Daily | ~10 days (1 vial) |
| Maintenance | 5 mg | 2–3× weekly | 8 weeks |
| Off-cycle | — | — | 4 weeks |
| Higher-end | 10 mg | Daily or alternate | Variable |
Combination effects. Almost no peptide combination has been studied as a combination in humans; stack logic is overwhelmingly mechanistic inference and community practice. Each linked compound has its own page.
Highest confidenceReported in peer-reviewed literature, registered clinical trials, or regulatory filings. Note the model: much peptide literature is in vitro or rodent work, not human trial data.
No trial has combined elamipretide with any other mitochondrial peptide.
Unproven — inference onlyExtrapolated from a known mechanism, receptor profile, or adjacent compound class. Biologically plausible but not directly demonstrated for this compound in this context.
The most mechanistically thought-through sequencing claim in the community canon: SS-31 restores membrane and cristae structure, then MOTS-c drives AMPK-mediated metabolic demand through the restored machinery. Repair the engine, then run it. Never tested, but coherently reasoned.
Electron transport requires NAD⁺; restoring cristae architecture without adequate NAD⁺ pools is arguably incomplete. Plausible and unstudied.
Structural mitochondrial repair alongside telomere and circadian claims — grouped together as a "longevity" pillar in community protocols rather than for any interaction mechanism.
If mitohormesis matters, chronic ROS suppression may blunt the adaptive signal that drives mitochondrial biogenesis from training. This is the one theoretical antagonism worth taking seriously and it is almost never raised.
Uncontrolled reportsAggregated from research-community logs, forums, vendor literature and self-reported experience. Uncontrolled, unverified, subject to placebo, polypharmacy and product-purity confounds. Lowest evidentiary weight.
The sequence in the Gold Standard protocol, run in that order over months.
Common in longevity-oriented stacks.
Whole schedules — dosing, titration, cycle length, and off-time — as documented in trials, as proposed from mechanism, and as circulated in the research community. Reproduced for study and comparison only.
Highest confidenceReported in peer-reviewed literature, registered clinical trials, or regulatory filings. Note the model: much peptide literature is in vitro or rodent work, not human trial data.
Registered protocols across primary mitochondrial myopathy, Barth syndrome, heart failure and dry AMD, with 40 mg daily subcutaneous as the predominant regimen and defined functional endpoints.
Unproven — inference onlyExtrapolated from a known mechanism, receptor profile, or adjacent compound class. Biologically plausible but not directly demonstrated for this compound in this context.
Restoring membrane architecture before stimulating metabolic demand is the coherent ordering, and the one the community protocol happens to use.
Given unknown long-term effects and the mitohormesis question, intermittent use limits the theoretical downside of chronic ROS suppression.
Uncontrolled reportsAggregated from research-community logs, forums, vendor literature and self-reported experience. Uncontrolled, unverified, subject to placebo, polypharmacy and product-purity confounds. Lowest evidentiary weight.
Start with SS-31 at 5 mg daily for one vial (~10 days) to address current structural stress, then step back to 5 mg two to three times weekly for eight weeks, then four weeks off. Add MOTS-c once the maintenance phase begins, then Epitalon last.
Grouped with MOTS-c, humanin, NAD⁺ and Epitalon in the mitochondrial and longevity category, initiated in the opening quarter as foundational.
SS-31 has a clinical record that almost nothing else in this library can match, and it reads as a warning rather than an endorsement. One accelerated approval in an ultra-rare disease, and three missed primary endpoints in the larger indications people actually cite it for. A compound can have a real, demonstrated mechanism and still fail repeatedly, and this is the clearest example of that on the site.
Elamipretide received FDA accelerated approval in September 2025, as Forzinity, to improve muscle strength in patients with Barth syndrome weighing at least 30 kg — the first approved therapy for that disease. Accelerated approval is granted on a surrogate or intermediate endpoint with confirmatory evidence still required, in a specific ultra-rare population. It is not an approval for mitochondrial dysfunction generally, and it is emphatically not an approval for use as a longevity compound.
Pathophysiology
Barth syndrome is an X-linked disorder caused by mutations in TAZ, the gene encoding tafazzin, which remodels cardiolipin. Abnormal cardiolipin destabilises the inner mitochondrial membrane, producing cardiomyopathy, skeletal myopathy, neutropenia and growth delay.
Mechanistic rationale
This is the one disease where the mechanism and the lesion are the same thing. SS-31 binds cardiolipin in the inner mitochondrial membrane and stabilises cristae structure and respiratory chain organisation. In a disease defined by defective cardiolipin remodelling, a cardiolipin-binding peptide is not an extrapolation. The TAZPOWER randomised crossover study and its open-label extension reported improved skeletal muscle strength and cardiac stroke volume, which supported the accelerated approval.
Community reports
A prescription therapy for an ultra-rare inherited disease, managed by specialist centres. Not a self-directed use.
Components carrying the argument: Cardiolipin binding, cristae stabilisation
Pathophysiology
Primary mitochondrial myopathies are inherited disorders of the respiratory chain producing exercise intolerance, weakness and fatigue, with no approved disease-modifying therapy.
Mechanistic rationale
This was the largest and most-watched programme for the compound, and the phase 3 MMPOWER-3 trial missed its primary endpoints on six-minute walk distance in 2023. That result matters more than any mechanistic argument: it is the properly powered test of the idea that stabilising cardiolipin improves function in general mitochondrial disease, and it did not deliver. Anyone citing SS-31 for mitochondrial dysfunction should be citing this trial.
Community reports
Community use for fatigue and mitochondrial complaints is common and generally unaware that the definitive trial in the closest matching population was negative.
Components carrying the argument: Same mechanism, broader population, no benefit shown
Pathophysiology
Cardiac muscle is the most mitochondria-dense tissue in the body, and impaired myocardial energetics is a well-described feature of heart failure.
Mechanistic rationale
The rationale was strong enough to run a trial, and the PROGRESS-HF programme missed its primary endpoint. Mitochondrial dysfunction in heart failure is real; correcting it with this compound did not translate into the outcome measured. This is the second of three.
Community reports
Cited in cardiovascular longevity contexts, usually on the mechanism rather than the result.
Components carrying the argument: Myocardial mitochondrial function
Pathophysiology
The retinal pigment epithelium has extremely high metabolic demand, and mitochondrial dysfunction in those cells is implicated in geographic atrophy.
Mechanistic rationale
The ReCLAIM programme did not meet its primary endpoints. Third trial, third miss, third tissue where the mechanistic case looked compelling. Taken together with MMPOWER-3 and PROGRESS-HF, the pattern is informative: the compound does something demonstrable at the mitochondrion, and translating that into a clinical outcome has worked in exactly one setting — the disease where the genetic lesion is in the pathway itself.
Community reports
Occasionally cited for eye health. The trial result is rarely mentioned alongside.
Components carrying the argument: Retinal pigment epithelium energetics
Pathophysiology
Mitochondrial function declines with age, and fatigue is a common symptom with a very long differential — anaemia, hypothyroidism, sleep apnoea, depression, medication effects and deconditioning among them.
Mechanistic rationale
This is the dominant reason people buy SS-31, and it is the use with the least support. Three randomised trials in populations with genuine, measurable mitochondrial pathology failed to show benefit on their primary endpoints. Expecting a larger effect in people whose mitochondria are merely ageing is the opposite of what that record predicts.
Community reports
Improved energy is commonly reported. It is among the most placebo-responsive endpoints in existence, and the common treatable causes of fatigue are diagnosable with a blood test and a sleep study.
Components carrying the argument: Cardiolipin stabilisation — unproven in this population
Pathophysiology
Ischaemia-reperfusion injury shares a common pathway across organs, with mitochondrial permeability transition as a central event.
Mechanistic rationale
Animal work spans kidney, heart, brain and skeletal muscle, and it is genuinely extensive. The clinical record above is the reason to hold that lightly — broad preclinical efficacy followed by repeated trial failure is a well-worn path, and this compound has now walked most of it.
Community reports
Cited in longevity contexts on the strength of the animal literature.
Components carrying the argument: Mitochondrial permeability transition, cristae integrity
| Indication | Trial | Result | The thing to know |
|---|---|---|---|
| Barth syndrome | TAZPOWER | Positive — approved Sept 2025 | The lesion is in the pathway itself |
| Primary mitochondrial myopathy | MMPOWER-3 | Missed primary endpoints | The definitive test of the general idea |
| Heart failure | PROGRESS-HF | Missed primary endpoint | Most mitochondria-dense tissue there is |
| Dry AMD | ReCLAIM | Missed primary endpoints | Third compelling rationale, third miss |
| Fatigue / ageing | None | — | The dominant use; least supported |
| Approval type | — | Accelerated | Confirmatory evidence still required |
For Barth syndrome and primary mitochondrial disease: specialist metabolic care, cardiac surveillance, management of neutropenia, physiotherapy and nutritional support. Elamipretide is now an option in Barth syndrome specifically, prescribed and monitored.
For fatigue: the diagnosable causes are worth excluding before anything else, because they are common and treatable — anaemia, iron deficiency, hypothyroidism, diabetes, sleep apnoea, depression, medication effects, and simple deconditioning. A blood panel and a sleep assessment answer most of it. Graded exercise, sleep regularity and treating depression have effect sizes no mitochondrial compound has demonstrated.
For heart failure: the four pillars — ACE inhibitor or ARNI, beta-blocker, mineralocorticoid receptor antagonist, SGLT2 inhibitor — each with independent mortality data. Cardiac rehabilitation is under-referred and improves survival.
For dry AMD: AREDS2 supplementation in the appropriate group, smoking cessation, and the complement inhibitors now approved for geographic atrophy with their modest effect and real injection burden.
Physical-chemistry reference for laboratory handling of the lyophilised material. Reproduced so that stability and concentration mathematics can be studied — see the calculator for the arithmetic and the reconstitution guide for sterile technique.
Supplied lyophilised, commonly 50 mg per vial in the research market. At 5 mg daily a 50 mg vial is ten days — which is exactly why circulating protocols describe the first phase as "one vial".
Lyophilised: −20 °C long-term. Reconstituted: 2–8 °C, protected from light.
Commonly 50 mg lyophilised vials.
The D-amino acid content of the sequence confers resistance to enzymatic degradation, contributing to stability relative to all-L peptides.
Regulatory status changes and differs by country. This is a summary for orientation, not legal advice — check your own jurisdiction.
Investigational. Elamipretide is a clinical-stage drug candidate (Stealth BioTherapeutics) with no marketing approval to date. Regulatory review has been pursued for Barth syndrome; approval status should be verified against current regulator listings.
Material sold as "SS-31" in the research market is not the clinical product and carries none of its manufacturing controls.
Regulatory and trial claims re-checked against primary sources on 16 August 2026. Checked: elamipretide FDA approval Sept 2025; MMPOWER-3, ReCLAIM, PROGRESS-HF. Approvals, trial readouts and compounding decisions move faster than anything else on this page — a date here means someone looked, not that nothing has changed since.
Athletes subject to WADA, USADA, UKAD, NCAA or military testing should assume any peptide is prohibited unless they have verified otherwise against the current WADA Prohibited List. Several classes here (growth-hormone secretagogues, TB-4 analogues, metabolic modulators) are explicitly named. Check the current list — it is republished annually.
Links resolve to PubMed records, trial registries, publisher pages or primary documents. Where a body of work rather than a single paper is cited, the link opens a PubMed query so the full result set — including newer papers than this page — can be reviewed. Verify every claim against the primary source before relying on it.
For educational and research reference only. Nothing on this site is medical advice, a recommendation, or an instruction to administer any substance to a human being. Every figure on this page is a record of what has been reported, not a recommendation. Full disclaimer.