SS-31 (Elamipretide)
Also known as: Elamipretide, MTP-131, Bendavia, Forzinity, Szeto-Schiller 31, D-Arg-Dmt-Lys-Phe-NH2
Lower numbers = closer to natural. Higher numbers = more enhanced.
Why this rating?
SS-31 is a cell-penetrating tetrapeptide that binds cardiolipin in the inner mitochondrial membrane, stabilises cristae, and reduces electron leak/ROS to improve ATP output. It targets mitochondrial dysfunction and is studied for longevity. It does not build muscle, alter hormones, or act as a classic performance-enhancer. In September 2025 its pharmaceutical form (Forzinity/elamipretide) received FDA accelerated approval for Barth syndrome, making it the first approved mitochondria-targeted drug. It is rated 1 (basically natty) because, at most, it helps mitochondria run at their normal capacity, supporting baseline energy/recovery rather than pushing muscle, fat loss, or hormones beyond the natural ceiling by any direct or indirect path.
Overview
A four-amino-acid, cell-penetrating peptide (sequence D-Arg-Dmt-Lys-Phe-NH2) from the Szeto-Schiller class that concentrates in the inner mitochondrial membrane and binds the phospholipid cardiolipin. By stabilising cardiolipin and the cristae architecture, it reduces oxidative stress and electron leak and helps mitochondria keep producing ATP efficiently. It is studied across mitochondrial dysfunction, heart failure, eye disease, and aging, and its pharmaceutical form was FDA-approved in 2025 for the rare disease Barth syndrome.
Purpose & Use Cases
Mitochondrial Dysfunction
Directly targets failing mitochondria by stabilising cardiolipin/cristae, the basis of its Barth-syndrome approval and its broader research program.
Longevity / Cellular Aging
Because mitochondrial decline is a hallmark of aging, it is used off-label in the longevity context to support bioenergetics and reduce oxidative stress.
Recovery & Energy
Users report better energy and recovery, attributed to improved mitochondrial ATP output, largely anecdotal outside approved indications.
Cardiac / Muscle Bioenergetics
Investigated for heart failure and mitochondrial myopathy; the approved indication is improving muscle strength in Barth syndrome.
Benefits
- Directly stabilises mitochondrial cardiolipin/cristae, a validated, drug-approved mechanism
- Reduces mitochondrial oxidative stress (ROS) and electron leak
- Supports ATP production and cellular energy
- First FDA-approved mitochondria-targeted therapeutic (as elamipretide/Forzinity)
- Non-hormonal: no PCT, no aromatization, no androgenic effects
- Generally well tolerated (mainly injection-site reactions)
Good to Know
The first FDA-approved mitochondria-targeted drug
In September 2025 the FDA granted accelerated approval to Forzinity (elamipretide HCl) to improve muscle strength in Barth syndrome, a major validation of the cardiolipin-targeting mechanism. Note the approval is narrow (an ultra-rare genetic disease), not a green light for anti-aging or performance use.
A mixed clinical record
SS-31 succeeded in Barth syndrome (TAZPOWER) but missed primary endpoints in several larger programs, including primary mitochondrial myopathy (MMPOWER-3) and studies in heart failure and dry AMD. Honest read: the mechanism is real and now drug-approved for one indication, but it is not a proven cure-all for general mitochondrial decline.
Targets a lipid, not a receptor
Unlike most peptides, SS-31 does not bind a cell-surface receptor. It concentrates thousands-fold in the inner mitochondrial membrane and works by binding cardiolipin and tuning membrane electrostatics, a fundamentally different mechanism from growth-factor or hormone peptides.
Not anabolic or androgenic
SS-31 does not build muscle, burn fat, aromatize, convert to DHT, or affect testosterone. No AI, no finasteride considerations, and no PCT apply. It is a bioenergetic/therapeutic peptide.
Likely not WADA-prohibited, but verify
SS-31/elamipretide is not explicitly named on the WADA Prohibited List and, being non-hormonal and non-anabolic, does not map cleanly to S2 or S4; FDA approval also removes any S0 "non-approved substance" argument for the drug form. Interpretations still vary, so tested athletes should confirm current status with their anti-doping authority.
Dosage Guidelines
| Experience Level | Dosage Range |
|---|---|
| Beginner | 1 – 3 mg/day |
| Intermediate | 3 – 10 mg/day |
| Advanced | 10 – 20 mg/day |
Community/research-chemical protocols (unverified, not clinically validated) typically titrate from ~5mg/day for the first 1-2 weeks up to a 10-20mg/day maintenance dose over 8-12 weeks, most experienced users favoring the low end (1-5mg/day) and citing diminishing returns above that. This is well below the fixed 40mg once-daily subcutaneous dose used in the FDA-approved Forzinity (Barth syndrome) label and the TAZPOWER trial, which is a disease-specific clinical dose, not a typical research/longevity protocol. There is no controlled dosing data for anti-aging or performance use. Reconstitute with bacteriostatic water and refrigerate.
Short in plasma; SS-31 concentrates in mitochondrial membranes rather than circulating freely.
Side Effects
Injection Site Reaction
very commonThe most common adverse effect in trials: in the pivotal Barth-syndrome study essentially all elamipretide-treated subjects had some site reaction (erythema, induration, pruritus, pain, or bruising), vs. a lower but still frequent rate on placebo. Described in the FDA label as mild-to-moderate.
Rotate sites; sterile technique; oral antihistamines or topical corticosteroids for persistent reactions.
Headache / Dizziness
uncommonMild headache or light-headedness reported in trials and by users.
Stay hydrated; lower dose if persistent.
GI Upset
uncommonOccasional nausea or stomach upset.
Usually transient.
Eosinophilia
commonElevated blood eosinophil counts occurred frequently in trials lasting 30+ days, typically peaking around 90 days and resolving within 6-12 months. Generally asymptomatic (no reported clinical manifestations) but is a real lab finding, not just anecdote.
Periodic bloodwork (CBC with differential) for longer-term use; discuss with a clinician if using beyond a few months.
Sourcing / Purity Risk
commonResearch-grade "SS-31" is not the regulated Forzinity product; purity and content vary by supplier.
Use a tested product with a certificate of analysis.
General Mitigation Strategies
SS-31 was well tolerated across a large clinical program, with injection-site reactions the predominant issue (near-universal but generally mild-to-moderate) and asymptomatic eosinophilia noted on bloodwork with longer use. Rotate injection sites, keep doses conservative for non-approved uses, and consider periodic CBC monitoring for extended protocols. Because research-grade material is not the FDA-approved drug, product quality is the main additional practical risk.
Post Cycle Therapy (PCT)
Not hormonal. Does not affect the HPTA or testosterone. No PCT required.
How It Works
SS-31 partitions into the inner mitochondrial membrane and associates selectively with cardiolipin, a phospholipid essential to cristae curvature and to the function of the electron-transport-chain complexes. As cardiolipin oxidises with age or disease, cristae destabilise and electrons leak, generating reactive oxygen species and reducing ATP yield. By binding cardiolipin and modulating the membrane's surface electrostatics and lipid packing, SS-31 preserves cristae structure, limits ROS generation, buffers calcium-related damage, and supports ATP production across the complexes. Its mechanism is lipid/membrane-based rather than acting through a cell-surface receptor.
Fundamentals
Reference on the practices relevant to SS-31 (Elamipretide): how they are done and where they go wrong. Not a recommendation to use it.
Common Stacks
- SS-31 + NAD+ - Mitochondrial-membrane protection plus redox/sirtuin support
- SS-31 + MOTS-c - Two-angle mitochondrial longevity stack
- SS-31 + Epithalon/GHK-Cu - Broader anti-aging protocol
Legal Status
FDA-approved as Forzinity (elamipretide) for Barth syndrome (Sept 2025), the first approved mitochondria-targeted drug. For all other/longevity uses it is off-label, and material sold as research-grade "SS-31" is not the regulated Forzinity product. Not approved for performance or anti-aging.
Legal status varies by country and changes over time. This is a general summary, not legal advice.
WADA Status
SS-31/elamipretide is not explicitly listed on the WADA Prohibited List. As a non-hormonal, non-anabolic mitochondrial peptide it does not fit S2 or S4 cleanly, and its 2025 FDA approval removes the S0 non-approved-substance argument for the drug form. Classification interpretations vary: verify current status before competition.
References
- Mitchell et al. 2020: SS-31 binds lipid bilayers and modulates surface electrostatics (mechanism, PMC7247319)
- Stealth BioTherapeutics: FDA accelerated approval of FORZINITY (elamipretide) for Barth syndrome, Sept 19 2025
- DailyMed, FORZINITY (elamipretide) full prescribing information: dosing, pharmacokinetics, adverse reactions