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    §LongevityResearch protocol

    SS-31.

    SS‑31 (elamipretide) is a mitochondria‑targeted tetrapeptide that selectively binds cardiolipin in the inner mitochondrial membrane[1], stabilizing electron transport chain complexes and reducing r...

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    Calculated-volume support unavailable

    This selected cited guide does not contain one unambiguous vial, per-event amount, cadence, and diluent set. No value was inferred from general library metadata. Review the cited table below before creating a private Research Use Only record.

    Cited protocol & reconstitution guide

    Source-backed reference fields by phase, including any volume fields authored in the cited guide.

    Tier 1 — Micro / sensitivity start

    0.1-1 mg

    Units / volume1–10 units (0.01–0.10 mL)

    Tier 2 — Low-dose maintenance (Weeks 8–12, with breaks)

    0.5-1 mg

    Units / volume5–10 units (0.05–0.10 mL)

    Tier 3 — Common reported range (Weeks 4–8)

    1-5 mg

    Units / volume10–50 units (0.10–0.50 mL)

    Tier 4 — Standard reported range

    5-10 mg

    Units / volume50–100 units (0.50–1.00 mL)

    Reconstitution by vial size

    Calculated volume for each cited phase and vial variant. The highlighted column matches the selection above.

    Phase
    10 mg
    1 mL water
    30 mg
    1.5 mL water
    50 mg
    2.5 mL water
    Tier 1 — Micro / sensitivity start———
    Tier 2 — Low-dose maintenance (Weeks 8–12, with breaks)———
    Tier 3 — Common reported range (Weeks 4–8)———
    Tier 4 — Standard reported range———
    Tier 5 — Higher-volume reports (Weeks 4–12)———

    Overview

    Overview

    SS‑31 (elamipretide) is a mitochondria‑targeted tetrapeptide that selectively binds cardiolipin in the inner mitochondrial membrane[1], stabilizing electron transport chain complexes and reducing reactive oxygen species production while enhancing ATP synthesis[2]. This peptide has demonstrated protective effects in preclinical models of heart failure, neurodegenerative disease, and age‑related muscle atrophy, and received FDA accelerated approval in 2025 as the first treatment for Barth syndrome

    Category
    Longevity
    Routes
    subcutaneous

    Mechanism

    SS-31

    Mechanism of action

    Mechanism of action

    SS‑31 (elamipretide) is a cell‑permeable tetrapeptide with a unique mechanism of action targeting mitochondrial dysfunction [1] . The peptide selectively accumulates in the inner mitochondrial membrane where it binds to cardiolipin, a specialized phospholipid essential for organizing electron transport chain supercomplexes and maintaining cristae structure [2] [7] . By stabilizing cardiolipin‑protein interactions, SS‑31 optimizes electron transport efficiency, reduces pathological reactive oxygen species generation, and enhances ATP synthesis in metabolically active tissues [8] . Preclinical research demonstrated that SS‑31 protects against mitochondrial dysfunction across multiple disease models including heart failure, ischemia‑reperfusion injury, neurodegeneration, chronic kidney disease, and age‑related muscle atrophy [9] . In human clinical trials, SS‑31 showed favorable safety and tolerability profiles with no dose‑limiting toxicities [4] [5] . While Phase II trials in heart failure and primary mitochondrial myopathy did not meet primary efficacy endpoints, the TAZPOWER trial in Barth syndrome demonstrated significant improvements in muscle strength and six‑minute walk distance, leading to FDA accelerated approval in 2025 [3] [10] .

    Key research findings
    • 01

      A mitochondria-targeting tetrapeptide (D-Arg-2',6'-dimethyl-Tyr-Lys-Phe-NH2) from the Szeto-Schiller (SS) peptide series; also known as elamipretide, MTP-131, and Bendavia. It concentrates in the inner mitochondrial membrane.

    • 02

      Mechanism: binds cardiolipin on the inner mitochondrial membrane, reported to stabilize cristae architecture, support electron-transport efficiency, and reduce mitochondrial reactive-oxygen-species production (in vitro and animal models).

    • 03

      Extensive preclinical literature across cardiac, renal, neural, ocular, and skeletal-muscle ischemia and aging models (animal studies).

    • 04

      Human trials (as elamipretide) have spanned heart failure, primary mitochondrial myopathy (MMPOWER series), dry age-related macular degeneration (ReCLAIM), and Barth syndrome (TAZPOWER); results were mixed, with some primary endpoints not met.

    • 05

      Regulatory milestone: in September 2025 the FDA granted accelerated approval to elamipretide (brand FORZINITY) for Barth syndrome; other indications remain investigational.

    Primary source: Barth syndrome (FDA-approved): TAZPOWER (NCT03098797) is the pivotal Phase 2/3 trial. The 12-week randomized crossover phase did not reach statistical significance vs placebo on either co-primary endpoint. The 168-week open-label extension showed durable improvements in 6-minute walk distance and knee extensor muscle strength. The natural-history comparison study (8 OLE patients vs 19 untreated controls) reinforced these findings. FDA granted accelerated approval on September 19, 2025 based on knee extensor strength as an intermediate endpoint. Heart failure: Multiple Phase 1–2 elamipretide studies in heart failure with preserved ejection fraction (HFpEF) and reduced ejection fraction (HFrEF) reported mixed and mostly modest signals. As of June 2026, no FDA approval exists in this indication. Primary mitochondrial myopathy: MMPOWER and MMPOWER-3 Phase 3 trials evaluated elamipretide in primary mitochondrial myopathy. MMPOWER-3 did not meet its co-primary endpoints. Stealth has continued exploration but the indication is not FDA-approved as of June 2026. Dry age-related macular degeneration: ReCLAIM and ReCLAIM-2 evaluated elamipretide in dry AMD. Mixed signals; investigational. Not FDA-approved for AMD as of June 2026. Mechanism and preclinical evidence: Strong and consistent. Cardiolipin binding, cristae stabilization, ATP rescue, and ROS reduction have been confirmed across cell-culture and animal disease models including ischemia-reperfusion injury, doxorubicin cardiotoxicity, age-related muscle dysfunction, and acute kidney injury models. Healthy-adult anti-aging or performance use: No published human RCT supports an anti-aging or athletic-performance indication for SS-31 in healthy adults. Anecdotes and supplier marketing are not evidence.

    Pharmacokinetic profile

    Literature reference (RUO)

    Single-dose plasma curve over 24h. Shaded band = commonly-cited therapeutic window. Illustrative only.

    Protocol Reference

    Protocol reference

    Research Use Only. PeptiJournal supports private research documentation and calculation support. It does not provide medical advice, human-use directions, or claims of safety or effectiveness.
    subcutaneous

    Commonly cited research range: 5–20 mg, daily.

    Reference figures reported in the research literature — not a dosing recommendation. For interactive vial math and scheduling, see the Calculator and Schedule tabs.

    Cited protocol & reconstitution guide

    Source-backed reference fields by phase, including any volume fields authored in the cited guide.

    Tier 1 — Micro / sensitivity start

    0.1-1 mg

    Units / volume1–10 units (0.01–0.10 mL)

    Tier 2 — Low-dose maintenance (Weeks 8–12, with breaks)

    0.5-1 mg

    Units / volume5–10 units (0.05–0.10 mL)

    Tier 3 — Common reported range (Weeks 4–8)

    1-5 mg

    Units / volume10–50 units (0.10–0.50 mL)

    Tier 4 — Standard reported range

    5-10 mg

    Units / volume50–100 units (0.50–1.00 mL)

    Titration protocol

    1. Micro / sensitivity startStart
      0.1-1 mg

      Subcutaneous. Daily or several times weekly. Rotate injection sites.

    2. Weeks 8–12 (with breaks)Build
      0.5-1 mg

      Subcutaneous, 3-5x/week. Observe the scheduled breaks as written; rotate sites.

    3. Weeks 4–8Build
      1-5 mg

      Subcutaneous, once daily at the same time each day. Skip a missed dose; do not double up.

    4. Standard reported rangeBuild
      5-10 mg

      Subcutaneous, once daily, often morning. Hold at this step before moving up.

    5. Weeks 4–12Maintenance
      10-20 mg

      Subcutaneous, once daily or pre-workout. At this vial's 10 mg/mL, any dose above 10 mg exceeds 100 units — split into two equal draws at separate sites (20 mg = 100 units (1.00 mL) × 2).

    Storage & Handling

    Storage requirements(typical for most peptides)

    ❄️
    Lyophilized (powder)
    -20°C (frozen)

    Can be stored for extended periods. Protect from moisture.

    🧊
    Reconstituted
    2-8°C (refrigerated)

    Store in refrigerator door. Never freeze after reconstitution.

    ⏱️
    Stability window
    28-30 days after reconstitution

    Label vials with reconstitution date. Discard if cloudy.

    Reconstitution steps

    1. 01🌡️01 Inspect the vial — Check the label, lot, and that the powder cake is intact and uncracked. Discard if damaged.
    2. 02🧴02 Bring to room temperature — Let the vial sit out 10–20 minutes after refrigeration so condensation does not form when you remove the cap.
    3. 03💉03 Wipe both stoppers — Use a fresh alcohol swab on the SS-31 vial stopper and on the BAC water vial stopper.
    4. 04💧Draw 1 mL bacteriostatic water into a sterile syringe — this 10 mg vial yields 10 mg/mL.
    5. 05🔄05 Inject slowly down the vial wall — Aim the stream against the inner glass wall, not directly onto the powder. This reduces foaming.
    6. 06🏷️06 Swirl, do not shake — Roll or gently swirl the vial until the solution is fully clear. Do not vortex or shake hard.
    7. 07❄️07 Label and store — Write the reconstitution date on the vial. Store reconstituted SS-31 refrigerated at 35.6–46.4°F (2–8°C), protected from light. Do not freeze once reconstituted.
    8. 08💉Important: This guide is for educational purposes only and is not medical advice. For research use only. Not for human consumption.
    9. 09💉This 10mg vial covers the first 4 steps of the schedule; later steps exceed one vial.

    Additional storage notes

    Forzinity (FDA-approved drug, 80 mg/mL solution)

    Refrigerated 36–46°F (2–8°C); do not freeze — After first opening, may be stored refrigerated or at room temp 68–77°F (20–25°C). Discard 8 days after first opening per label.

    Lyophilized research-use SS-31 (powder)

    -4°F (-20°C) long-term; refrigerated short-term — Use original sealed vial, away from light. Stability typically reported up to ~2 years frozen by suppliers, but verify supplier label and stability data.

    Reconstituted research-use SS-31 (liquid)

    35.6–46.4°F (2–8°C) — Do not freeze. Protect from light. Many suppliers and protocol references suggest using within ~28 days of reconstitution.

    Clinical Evidence

    Clinical evidence

    Investigated in preclinical and clinical research for mitochondrial dysfunction in cardiac, muscle, and ophthalmic contexts.

    Barth syndrome (FDA-approved): TAZPOWER (NCT03098797) is the pivotal Phase 2/3 trial. The 12-week randomized crossover phase did not reach statistical significance vs placebo on either co-primary endpoint. The 168-week open-label extension showed durable improvements in 6-minute walk distance and knee extensor muscle strength. The natural-history comparison study (8 OLE patients vs 19 untreated controls) reinforced these findings. FDA granted accelerated approval on September 19, 2025 based on knee extensor strength as an intermediate endpoint. Heart failure: Multiple Phase 1–2 elamipretide studies in heart failure with preserved ejection fraction (HFpEF) and reduced ejection fraction (HFrEF) reported mixed and mostly modest signals. As of June 2026, no FDA approval exists in this indication. Primary mitochondrial myopathy: MMPOWER and MMPOWER-3 Phase 3 trials evaluated elamipretide in primary mitochondrial myopathy. MMPOWER-3 did not meet its co-primary endpoints. Stealth has continued exploration but the indication is not FDA-approved as of June 2026. Dry age-related macular degeneration: ReCLAIM and ReCLAIM-2 evaluated elamipretide in dry AMD. Mixed signals; investigational. Not FDA-approved for AMD as of June 2026. Mechanism and preclinical evidence: Strong and consistent. Cardiolipin binding, cristae stabilization, ATP rescue, and ROS reduction have been confirmed across cell-culture and animal disease models including ischemia-reperfusion injury, doxorubicin cardiotoxicity, age-related muscle dysfunction, and acute kidney injury models. Healthy-adult anti-aging or performance use: No published human RCT supports an anti-aging or athletic-performance indication for SS-31 in healthy adults. Anecdotes and supplier marketing are not evidence.

    1. 01A mitochondria-targeting tetrapeptide (D-Arg-2',6'-dimethyl-Tyr-Lys-Phe-NH2) from the Szeto-Schiller (SS) peptide series; also known as elamipretide, MTP-131, and Bendavia. It concentrates in the inner mitochondrial membrane.
    2. 02Mechanism: binds cardiolipin on the inner mitochondrial membrane, reported to stabilize cristae architecture, support electron-transport efficiency, and reduce mitochondrial reactive-oxygen-species production (in vitro and animal models).
    3. 03Extensive preclinical literature across cardiac, renal, neural, ocular, and skeletal-muscle ischemia and aging models (animal studies).
    4. 04Human trials (as elamipretide) have spanned heart failure, primary mitochondrial myopathy (MMPOWER series), dry age-related macular degeneration (ReCLAIM), and Barth syndrome (TAZPOWER); results were mixed, with some primary endpoints not met.
    5. 05Regulatory milestone: in September 2025 the FDA granted accelerated approval to elamipretide (brand FORZINITY) for Barth syndrome; other indications remain investigational.

    Evidence maturity varies by compound; much peptide research is preclinical (in vitro or animal-model). Where human data are limited, findings should be read as research observations, not clinical conclusions.

    References

    Literature references

    Published research articles and sources related to SS-31.

    1. 01
      U.S. Food and Drug Administration. FORZINITY (elamipretide) injection — Highlights of Prescribing Information. accessdata.fda.gov (2025)
      et al. (2025)
    2. 02
      U.S. Food and Drug Administration, Center for Drug Evaluation and Research. Approval Package for Application 215244Orig1s000 (FORZINITY). accessdata.fda.gov (2025)
      et al. (2025)
    3. 03
      Stealth BioTherapeutics Inc. FDA Accelerated Approval of FORZINITY (elamipretide HCl), the First Therapy for Barth Syndrome — News Release. PR Newswire (2025)
      et al. (2025)
    4. 04
      Shirley M. Elamipretide: First Approval. Drugs (PubMed) (2025)
      et al. (2025)
    5. 05
      Reid Thompson WR, Hornby B, Manuel R, et al. Long-term efficacy and safety of elamipretide in patients with Barth syndrome: 168-week open-label extension results of TAZPOWER. Genetics in Medicine (2024)
      et al. (2024)
    6. 06
      Reid Thompson WR, Manuel R, Abbruscato A, et al. Natural history comparison study to assess the efficacy of elamipretide in patients with Barth syndrome. Orphanet Journal of Rare Diseases (PMC) (2022)
      et al. (2022)
    7. 07
      Mitchell W, Ng EA, Tamucci JD, et al. The mitochondria-targeted peptide SS-31 binds lipid bilayers and modulates surface electrostatics as a key component of its mechanism of action. Journal of Biological Chemistry (PMC) (2020)
      et al. (2020)
    8. 08
      Chavez JD, Tang X, Campbell MD, et al. Mitochondrial protein interaction landscape of SS-31. Proceedings of the National Academy of Sciences (PNAS) (2020)
      et al. (2020)
    9. 09
      Daubert MA, Yow E, Dunn G, et al. Elamipretide: A Review of Its Structure, Mechanism of Action, and Therapeutic Potential. International Journal of Molecular Sciences (PMC) (2025)
      et al. (2025)
    10. 10
      Sabbah HN. Barth syndrome cardiomyopathy: targeting the mitochondria with elamipretide. Heart Failure Reviews (PubMed) (2021)
      et al. (2021)
    11. 11
      Barth Syndrome Foundation. FDA Approves First Medication for Barth Syndrome (FORZINITY). barthsyndrome.org (2025)
      et al. (2025)
    12. 12
      ClinicalTrials.gov. Study to Evaluate the Safety, Tolerability, and Efficacy of Elamipretide in Subjects With Barth Syndrome (TAZPOWER, NCT03098797). clinicaltrials.gov (2025)
      et al. (2025)
    13. 13
      Peptides Institute. SS-31: Research Profile & Guide. peptidesinstitute.org (2026)
      et al. (2026)
    14. 14
      Pep-Pedia. SS-31 (Elamipretide). pep-pedia.org (2026)
      et al. (2026)
    15. 15
      Peptide Protocol Wiki. SS-31: Community Protocols & Reports. peptideprotocolwiki.com (2026)
      et al. (2026)
    16. 16
      Reddit r/Peptides. SS-31 - Dosing and Results? reddit.com (2024)
      et al. (2024)
    17. 17
      Reddit r/Peptidesource. SS31 protocol. reddit.com (2026)
      et al. (2026)
    Search PubMed for SS-31

    Observed Effects

    Observed effects in cited research

    Most commonly reported in trials
    • Injection-site reactions: redness, swelling, itching, or mild pain. These were the most common adverse events in TAZPOWER and the long-term extension.
    • Headache, especially in the first weeks of dosing.
    • Dizziness, mild nausea, or fatigue, mostly self-limited.
    Notable per the Forzinity label
    • Hypersensitivity reactions. Serious hypersensitivity has been observed; the label lists hypersensitivity as a contraindication for any ingredient.
    • Benzyl alcohol content. Forzinity contains benzyl alcohol; not for use in neonates due to risk of metabolic acidosis and gasping syndrome with benzyl-alcohol-containing drugs.
    • Renal impairment. Elamipretide and inactive metabolites accumulate in severe renal impairment; the label requires a 20 mg/day dose in adults with eGFR <30 mL/min not on dialysis.
    Theoretical and quality-control risks
    • Drug interactions: per the FDA label and Epocrates, no significant interactions have been identified, but kidney-stressing co-medications deserve clinician attention because elamipretide is renally cleared.
    • Quality control of research-use vials: research-use SS-31 is not subject to FDA manufacturing oversight. Purity, identity, and endotoxin content can vary by supplier and lot. Buyer-side verification (COA review) is the only consumer-side check.
    • Long-term safety beyond ~3.5 years (the longest TAZPOWER OLE follow-up) in healthy adults is not established. The trial population was small and tightly defined.
    Stop and seek qualified medical care for
    • Any sign of allergic reaction, spreading or infected injection-site reactions, persistent severe headaches, new shortness of breath or chest symptoms, significant changes in urination or new swelling, or any observed effect that significantly affects daily function. PDP does not provide medical advice.

    Research Considerations

    Research considerations

    Research Use Only - not for human or veterinary therapeutic use. Investigational compound currently in clinical development; not approved for general use. Consult a licensed healthcare professional for any clinical decisions.

    • Patients with serious hypersensitivity to elamipretide or any ingredient in the formulation.
    • Neonates (the vial contains benzyl alcohol; benzyl-alcohol-containing drugs have caused serious adverse reactions in low-birth-weight and preterm neonates).
    • Adults with severe renal impairment (eGFR <30 mL/min, not on dialysis): the label specifies a 20 mg daily dose adjustment.
    • Adults with eGFR <30 mL/min on dialysis: insufficient data per label; no recommended regimen.
    • Pregnancy and lactation: data are limited; refer to the prescriber.
    • Healthy adults seeking anti-aging, cognitive, or athletic-performance benefits.
    • Patients with primary mitochondrial myopathy, heart failure, or dry age-related macular degeneration. Some of these have been studied (MMPOWER, MMPOWER-3, ReCLAIM/ReCLAIM-2), but as of June 2026 none has produced an FDA approval, and Stealth's continued investigation in dry AMD and primary mitochondrial myopathy remains exactly that — investigation.
    • Patients under 30 kg.

    Factors noted in the research literature; not patient-specific medical advice.

    Regulatory Status

    Regulatory status

    RUO

    Research Use Only. PeptiJournal supports private research documentation and calculation support. It does not provide medical advice, human-use directions, or claims of safety or effectiveness.

    Comparisons

    Comparisons

    CompoundMechanismRouteStatus
    SS-31thisA mitochondria-targeted tetrapeptide that selectively binds cardiolipin in the inner mitochondrial membrane, stabilizing electron-transport-chain organization and reducing reactive oxygen species.subcutaneousInvestigational / RUO
    TestagenA synthetic tetrapeptide bioregulator (Lys-Glu-Asp-Gly) studied for modulation of endocrine function, particularly pituitary-gonadal regulatory pathways.subcutaneousInvestigational / RUO
    Vesugen (Lys-Glu-Asp)A synthetic tripeptide bioregulator (Lys-Glu-Asp) studied for gene-regulatory support of vascular endothelial tissue.subcutaneousInvestigational / RUO
    VilonA synthetic immunoregulatory dipeptide (Lys-Glu) studied for gene-regulatory and immunomodulatory activity, including effects on lymphocyte markers and chromatin structure.subcutaneousInvestigational / RUO
    CartalaxA synthetic tripeptide bioregulator (Ala-Glu-Asp) studied for gene-regulatory activity in connective and cartilage tissue, with proposed anti-inflammatory and regenerative effects.subcutaneousInvestigational / RUO
    SurvodutideAn investigational long-acting dual agonist of GLP-1 and glucagon receptors studied for appetite regulation and increased energy expenditure.subcutaneousInvestigational / RUO
    TB-500Upregulates actin, promotes cell migration, reduces inflammation, and stimulates wound healing and tissue repair.subcutaneous, intramuscularInvestigational / RUO

    Attributes shown for research comparison only; not a statement of efficacy or therapeutic equivalence.

    FAQ

    Frequently asked questions

    Research-use notice

    Research Use Only. This educational content and calculation support is intended for private research documentation. It does not provide medical advice, human-use directions, or claims of safety or effectiveness.

    Cited guide source: View source

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