Verified July 2026 · Cited to primary sources

SS-31 (Elamipretide): Evidence Grade C. Early / foreign human data only.

Grade CResearch-onlySafety: amber

The honest verdict

The most legitimate science on this list, and still not a green light. Elamipretide is a real drug candidate with a plausible mitochondrial mechanism and clean tolerability, but its flagship mitochondrial-myopathy Phase 3 missed its endpoints. The dry-AMD program is the one to watch. Until a Phase 3 reads out positive and it earns approval, treat grey-market SS-31 as an unproven, unapproved injectable and keep expectations low.

SS-31 (Elamipretide) at a glance

Class
Mitochondria-targeted tetrapeptide
Mechanism
Elamipretide is a small cell-permeable tetrapeptide (D-Arg-dimethylTyr-Lys-Phe-NH2) that concentrates in the inner mitochondrial membrane and binds cardiolipin. By stabilizing cardiolipin and the associated respiratory-chain supercomplexes, it is proposed to improve electron transport efficiency, reduce reactive oxygen species, and restore ATP production in mitochondria that are dysfunctional. Because mitochondrial dysfunction sits underneath many age-related and rare diseases, it has been tested across mitochondrial myopathy, heart failure, and dry age-related macular degeneration.
Also known as
elamipretide, MTP-131, Bendavia, SS 31
Research applications
  • Primary mitochondrial myopathy
  • Dry age-related macular degeneration / geographic atrophy
  • Heart failure and ischemia-reperfusion
  • Mitochondrial dysfunction and aging models
Forms
Subcutaneous injection (investigational, trial supply), Grey-market lyophilized powder
Legal status
Research-only
WADA (anti-doping)
Not specifically listed by WADA; as an investigational unapproved drug it should be treated as prohibited under the S0 non-approved-substances catch-all
Evidence grade
Grade CEarly / foreign human data only

How we grade evidence

Every grade comes from a fixed A to F rubric: human-trial strength, not hype or affiliate status. Last verified July 6, 2026.

What is SS-31 (Elamipretide)?

The most seriously studied peptide on this list, run through real Phase 3 trials. Its flagship mitochondrial-myopathy trial missed its primary endpoints, but its dry-AMD program is still advancing, so the honest verdict is mixed, not settled.

Elamipretide is a small cell-permeable tetrapeptide (D-Arg-dimethylTyr-Lys-Phe-NH2) that concentrates in the inner mitochondrial membrane and binds cardiolipin. By stabilizing cardiolipin and the associated respiratory-chain supercomplexes, it is proposed to improve electron transport efficiency, reduce reactive oxygen species, and restore ATP production in mitochondria that are dysfunctional. Because mitochondrial dysfunction sits underneath many age-related and rare diseases, it has been tested across mitochondrial myopathy, heart failure, and dry age-related macular degeneration.

How strong is the evidence for SS-31 (Elamipretide)?

There is genuine human trial data, which is more than most peptides here can claim, but the results are mixed. The pivotal Phase 3 MMPOWER-3 trial in primary mitochondrial myopathy (218 patients) missed both primary endpoints: the 6-minute walk test difference was -3.2 m (p=0.69) and the fatigue score difference was -0.07 (p=0.37). Separately, the dry-AMD program produced a positive Phase 2 ellipsoid-zone signal that was strong enough to carry a regulatory-accepted endpoint into the ongoing Phase 3 ReNEW study. So: a failed flagship indication alongside a live, better-looking one. Grade C reflects human trials of genuinely mixed results, not a clean win. It is not yet approved for anything.

Primary sources (3)

  1. Karaa A, et al. Efficacy and Safety of Elamipretide in Primary Mitochondrial Myopathy: MMPOWER-3 Randomized Clinical Trial. Neurology, 2023;101(3):e238-e252.
  2. ReNEW: Phase 3 Study of Subcutaneous Elamipretide in Dry Age-Related Macular Degeneration (ongoing).
  3. Genotype-specific effects of elamipretide in primary mitochondrial myopathy: post hoc analysis of MMPOWER-3. Orphanet J Rare Dis, 2024.

What is SS-31 (Elamipretide) used for?

SS-31 (Elamipretide) is marketed for the goals below. See how it ranks against other peptides in each, by evidence, not hype.

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What does SS-31 (Elamipretide) cost, and how do you access it legally?

Typical cost

$45 to $90 per 10 mg to 50 mg vial (grey-market research supply)

Grey-market pricing has nothing to do with the trial drug's cost or quality. You are paying research-chemical prices for an unapproved compound; the real clinical material is only available inside trials.

No legal supervised access route right now.

SS-31 (Elamipretide) has no compliant US route today. Vials sold "for research use only" are a gray-market fig-leaf, not a legal loophole, so we don't link them. If you pursue SS-31 (Elamipretide), do it with a licensed clinician, and re-check its legal status first.

Is SS-31 (Elamipretide)safe? Side effects & risks

Limited human safety data, no major documented harms

Elamipretide has a relatively clean safety record across trials, with injection-site reactions the most common adverse event and most events mild to moderate. But it is investigational and not FDA-approved for any use, so it is not a compoundable or prescription product. Grey-market SS-31 sold as a research chemical has no purity guarantees and is not the trial formulation. Anyone considering it should recognize they are self-administering an unapproved injectable drug that failed its lead efficacy trial.

Medical disclaimer: This page is independent editorial information, not medical advice, and Best Peptide For That is not a medical provider. We do not provide dosing. Talk to a licensed clinician before starting, stopping, or changing any peptide or medication. Full medical disclaimer.

FAQ

SS-31 (Elamipretide) FAQ

Did the SS-31 clinical trials succeed?

Mixed. The Phase 3 MMPOWER-3 trial in mitochondrial myopathy missed both primary endpoints (6-minute walk and fatigue). The dry age-related macular degeneration program had a positive Phase 2 signal and is being tested in an ongoing Phase 3, so it is not a clean success or a clean failure.

Is elamipretide FDA-approved?

No. It remains investigational and is not approved for any indication as of mid-2026. That is why it is research-only rather than a prescription or compounded product.

What is SS-31 supposed to do?

It targets the inner mitochondrial membrane and binds cardiolipin to stabilize the respiratory chain, with the goal of improving ATP production and lowering oxidative stress in dysfunctional mitochondria.

Is SS-31 safe?

In trials it was generally well tolerated, mostly injection-site reactions. But grey-market SS-31 is not the trial formulation, has no purity verification, and is an unapproved injectable, so the trial safety record does not transfer to what is sold online.

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