SS-31

Areas of active research — not promised effects

Each tag links to other compounds with research into that goal. Research use only: these are areas of study, not human-use claims.

Related by research scope · open each to compare

Elamipretide is a Schedule-℞ prescription medicine in the United States. Outside its approved indication (Barth syndrome, ≥30 kg), it remains investigational. Compounding of elamipretide as a bulk API by 503A/503B pharmacies for non-Barth indications is legally problematic because it is now an FDA-approved active ingredient; specific compounding guidance from FDA had not been published as of May 2026.

Transparent blend · bci-1.0 · never paid-placement

Primary name

SS-31

Origin

Synthetic tetrapeptide (D-Arg-2,6-dimethyl-Tyr-Lys-Phe-NH2) designed by Hazel Szeto and Peter Schiller at Weill Cornell Medical College to selectively accumulate at the inner mitochondrial membrane via electrostatic attraction to cardiolipin.

Registry IDs

PubChem CID

11764719

CAS

736992-21-5

InChIKey

SFVLTCAESLKEHH-WKAQUBQDSA-N

DrugBank

DB11981

ChEMBL

CHEMBL3833370

Molecular formula

C32H49N9O5

Molar mass

639.8 g/mol

Monoisotopic

639.38566570 Da

InChIKey

SFVLTCAESLKEHH-WKAQUBQDSA-N

Appearance

White to off-white lyophilised powder

Solubility

Freely soluble in water; soluble in normal saline and bacteriostatic water for i…

Sequence not available in current seed.

Stability: Stable as lyophilised solid; subject to oxidation and aggregation in solution, particularly at elevated temperature or pH extremes. Cardiolipin-binding activity

Vial sizes

5 mg

Purity grades

research grade (>95% HPLC) / pharmaceutical grade (GMP, Forzinity)

Salt forms

Free base (primary)

• GHS hazard class on file
• PPE & spill response
• Disposal guidance
• Not-for-human-consumption posture

How much research exists, and of what maturity — never a verdict on whether it works.

Mechanism of action

• Elamipretide carries alternating aromatic and cationic residues that give it a net positive charge, driving rapid energy-independent accumulation (1,000- to 5,000-fold) at the highly anionic inner mitochondrial membrane
• There it binds reversibly to cardiolipin, a phospholipid essential for organising electron transport chain (ETC) supercomplexes; this binding stabilises cristae architecture and reduces cardiolipin peroxidation
• Downstream effects include improved ETC efficiency and enhanced ATP synthesis, reduced superoxide/reactive oxygen species leakage, and modulation of ADP/ATP translocase (ANT1) to lower proton leak
• Secondary protein interactions—including with Complex IV subunit NDUA4 and the inner membrane scaffold prohibitin 2—further support mitochondrial biogenesis and turnover

Pharmacokinetics (ADME)

Half-life

~3.5 h plasma half-life (subcutaneous); tissue half-life in mitochondria-rich organs estimated 18–24 h due to cardiolipin binding

Clearance

Not formally published in peer-reviewed sources; dose-proportional PK observed across studied dose range

PK–PD note: Absolute subcutaneous bioavailability reported ~92% in preclinical/early clinical data; Tmax ~0.5–1 h; plasma protein binding ~39%. Tissue retention substantially outlasts plasma half-life. PK data fo…

Reading the evidence

• Evidence quality and gaps vary by application — see the cited grades above.
• Indexed-article counts span all evidence tiers, not only completed human trials.
• No first-party human-dosing, efficacy, or benefit claims are made here.

Key reviews & evidence-gap sources

• Tung C, et al. Elamipretide: A Review of Its Structure, Mechanism of Action, and Therapeutic Potential. Int J Mol Sci. 2025;26(3):944. — Anchoring mechanistic/therapeutic review (PMID 39940712)
• Thompson WR, et al. A phase 2/3 randomized clinical trial followed by an open-label extension to evaluate the effectiveness of elamipretide in Barth syndrome. (TAZPOWER) — Primary RCT publication for Barth syndrome indication
• Efficacy and Safety of Elamipretide in Individuals With Primary Mitochondrial Myopathy: The MMPOWER-3 Randomized Clinical Trial. Neurology. — Phase 3 RCT; failed to meet primary endpoints (6MWT, PMMSA TFS)
• Long-term efficacy and safety of elamipretide in patients with Barth syndrome: 168-week open-label extension results of TAZPOWER. Genetics in Medicine. 2024;26(7):101138.
• FDA Press Announcement: FDA Grants Accelerated Approval to First Treatment for Barth Syndrome (Forzinity/elamipretide), Sept 19, 2025 — Regulatory approval; accelerated approval based on knee extensor muscle strength intermediate endpoint

1 registered trial — 0 currently recruiting.

Phase 1
NCT05168774
FRDA Investigator Initiated Study (IIS) With Elamipretide

COMPLETED

Summary (literature)

In clinical trials (Barth syndrome, primary mitochondrial myopathy, AMD), the most frequently reported adverse events were mild-to-moderate injection-site reactions (erythema, pain, pruritus). Hypersensitivity reactions are flagged in the Forzinity prescribing information. The ap…

WADA status

Not specifically listed on the WADA 2026 Prohibited List. However, WADA's general provisions prohibit peptide hormones, growth factors, related substances, and …

Dominant research route: Subcutaneous (SC)

Humans (Barth syndrome TAZPOWER Phase 2/3 and 168-week open-label extension; primary mitochondrial myopathy; HFrEF subcutaneous programs); FDA-approved route for Forzinity (40 mg once daily SC)

Bioavailability: Absolute bioavailability following subcutaneous administration is approximately 92%; Tmax 0.5–1 h; terminal half-life ~4 h.

Dominant clinical and approved route. FORZINITY label specifies 40 mg SC once daily for Barth syndrome in patients ≥30 kg. Most common adverse events were mild-to-moderate injection-site reactions.

Humans (Phase I ascending-dose in healthy subjects 0.01–0.25 mg/kg/h over 4 h; EMBRACE HFrEF trial single 4-h infusion 0.005/0.05/0.25 mg/kg/h; MMPOWER Barth syndrome 0.01–0.25 mg/kg/day); preclinical canine heart failure

Bioavailability: IV reference route; peak plasma concentrations occurred at end of 4-h infusion and were undetectable by 24 h post-infusion in the EMBRACE trial.

Used in early Phase I/II acute and short-duration settings; SC superseded IV for chronic outpatient dosing. Well-tolerated across a wide IV dose range with stable blood pressure and heart rate.

Humans (Phase I safety/tolerability/PK in healthy male and female subjects with oral dosing, per Szeto 2014); no approved oral formulation

Bioavailability: Oral dosing was assessed in Phase I for safety/tolerability/PK; quantitative oral bioavailability not established in retrieved sources. SS-31 is a tetrapeptide subject to proteolytic degradation; oral bioavailability is not described in any approved protocol.

Oral route was explored only in early Phase I; never advanced to pivotal trials or approval. Oral stability (protease susceptibility) is distinct from oral absorption and limits development.

Animal & human figures are kept visibly separate so studied animal doses are never misread as human guidance.

Sorted A–Z by vendor — never by price

Weekly median $/mg from the live vendor crawl.

Researched storefront prices, bucketed

p25 $3.63 · median $4.52 · p75 $6.00 · 7 researched vendors

Legit, COA-backed band: $3.00–$7.00/mg.

Value rule: don't just buy the cheapest — a price under $3/mg is a red flag. Pair price with COA and independent-test grade.

Estimated cost of research (10 mg)

Vial (best researched price)

$28

Bacteriostatic water (generic estimate)

$6

Syringes / supplies (generic estimate)

$12

What each test proves — general guidance, plus this compound's researched purity data

Purity on the current market (researched)

Vendor-reported purity ranges from ≥98% to >99.8%. One batch (Grail Formula / 24Peptides, tested by Liquilabs s.r.o.) reported >99.8% purity with assay content verified at 56.3 mg per 50 mg label. Multiple research-grade vendors claim ≥99% purity with HPLC-MS testing. Independent aggregator guidance states 'typically 98%+' for SS-31 from reputable providers.

Independent labs cited for this compound

No FDA recalls, enforcement actions, or warning letters specifically naming SS-31 (elamipretide) as a compound were found in the searched sources. General FDA warning letters targeting peptide vendors (e.g., Gram Peptides, USApeptide.com, Prime Peptides) cite unapproved new drug violations for other peptides (semaglutide, retatrutide, tirzepatide) but do not specifically name SS-31/elamipretide.

Buyer red-flag checklist

• SS-31 (elamipretide) is FDA-approved only for Barth syndrome; marketing for anti-aging, energy, or other off-label uses may draw FDA/FTC enforcement attention.
• Research-use SS-31 is not subject to FDA manufacturing oversight; purity, identity, and endotoxin content can vary by supplier and lot.
• Compounded or gray-market peptide products are described as 'frequent enforcement targets' by legal compliance sources.
• An SS-31 vial without HPLC purity above 98%, mass spec confirmation, and endotoxin data cannot be assumed safe for injection.
• Clinical elamipretide (FORZINITY) is not commercially available outside specialty pharmacy for Barth syndrome; any SS-31 sold online outside that channel is research-grade material.
• SS-31 contains an unusual 2,6-dimethyltyrosine (Dmt) residue; a legitimate COA should confirm this modification via mass spectrometry.
• No specific FDA warning letters or recalls naming SS-31/elamipretide were found, but the compound's recent FDA approval (Sept 2025) increases regulatory scrutiny risk for off-label sellers.

GMP vs research-grade: the chemistry (SPPS + HPLC + MS) is identical — the difference is the quality system.

Underdosing / mislabeling: No independent lab test data (Janoshik, MZ Biolabs, Finnrick, or similar) specifically documenting underdosing prevalence for SS-31 (elamipretide) was found in the searched sources. Janoshik lists an elamipretide (SS-31) analysis service and has published at least one raw data file for a Skye Peptides SS-31 sample, but the specific purity/assay result could not be extracted from the retrieved PDF. No aggregate underdosing rate is available.

• Import Alert 66-41: 'Detention Without Physical Examination of Unapproved New Drugs Promoted In The U.S.' Unapproved new drugs — including peptides promoted for disease treatment or structure/function effects without FDA approval — may be detained without physical examination. SS-31 (elamipretide) is FDA-approved only for Barth syndrome (FORZINITY); research-grade SS-31 sold or promoted for unapproved uses could fall within scope of this alert.66-41
• An RUO label is not an import exemption — CBP judges actual intended use.
• Lyophilized powder is ambient-stable in transit; temperature control needed for > 7-day transit.
• US-warehouse vendors dodge import scrutiny — they cost more but ship more reliably.

Every item dated & sourced

Not listed on the WADA Prohibited List (2025-2026); elamipretide is not explicitly prohibited. Athletes should verify with national anti-doping authorities.

No granted patents identified in current seed. Composition-of-matter coverage is limited given the peptide's synthetic origin.

• IACUC / IRB research context
• RUO buyer responsibilities & documentation
• Veterinary / alternative-use where lawful
• Jurisdiction-aware "who may lawfully obtain"

What people discuss

Reported concerns — discussion, not established effects

Reading caveats

• Vendor-affiliated content (realpeptides.co, injectco.com are commerce sites framing community sentiment)
• Self-experimenter anecdote with no controlled dosing
• Small de-identified sample concentrated in chronic-illness subreddits (selection skew toward symptomatic users)
• Dose extrapolation from mouse anti-aging studies to human self-administration
• Reddit echo-chamber / upvote amplification of outlier reports
• Aggregator pages (Peptide Protocol Wiki) synthesize from forums without primary verification

Manually researched from reddit, youtube— theme weights are research estimates, not live counts; aggregated & de-identified. No individual posts, quotes, or usernames are ever shown.

Relative research / market volume — populated once the activity stream is wired

Inline tooltips for lyophilized, RUO, EU/mg, SPPS, 503A and more.

Toggle plain-language ↔ scientific in the header.

• How to read a COA
• Free base vs acetate
• Understanding evidence grades

Mitochondria-targeting tetrapeptide that binds cardiolipin on the inner mitochondrial membrane; FDA-approved (Forzinity) for Barth syndrome since September 2025. Approximately 272 articles are indexed (literature last scanned 2026-05-29). US regulatory status: FDA-approved prescription drug (Forzinity, NDA 215244) under accelerated approval for Barth syndrome; investigational for all other indications. Research use only.

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