SS-31 (Elamipretide) vs TB-500 (Thymosin Beta-4)

Side-by-side comparison of mechanisms, dosing, interactions, and stacking potential.

SS-31 (Elamipretide)TB-500 (Thymosin Beta-4)
CategoryPeptidesPeptides
Standard DoseResearch indicates 0.05-0.25 mg/kg daily via subcutaneous injection. Clinical trials used 4-40 mg/day IV or SC.Research indicates 2-2.5 mg administered twice weekly via subcutaneous injection.
TimingMorning dosing preferred. No food timing restrictions.No strict timing requirements. Can be administered at any time of day. Systemic action means injection location is not critical.
Cycle DurationClinical trials ranged from single dose to 48 weeks. Optimal cycle length not established.Loading phase: 4-6 weeks. Total cycle: 8-16 weeks.
Evidence LevelEmerging (Phase 2/3 trials)animal_plus_anecdotal

Mechanism

SS-31 (D-Arg-Dmt-Lys-Phe-NH2, also known as elamipretide/Bendavia) is a cell-permeable tetrapeptide that localizes to the inner mitochondrial membrane and binds cardiolipin via electrostatic interactions. This stabilizes cardiolipin against oxidative damage, preserving cristae integrity, reducing ROS production, and maintaining mitochondrial ATP production. SS-31 interacts with proteins in two functional groups: oxidative phosphorylation complexes and 2-oxoglutarate metabolic enzymes — all known cardiolipin binders. It restores mitochondrial function without acting as a direct antioxidant.

Standard Dosing

Research indicates 0.05-0.25 mg/kg daily via subcutaneous injection. Clinical trials used 4-40 mg/day IV or SC.

Timing

Morning dosing preferred. No food timing restrictions.

Cycle Duration

Clinical trials ranged from single dose to 48 weeks. Optimal cycle length not established.

Side Effects

  • Injection site reactions
  • Headache
  • Diarrhea (in clinical trials)
  • Nausea

Contraindications

  • Pregnancy and breastfeeding
  • Severe renal impairment (peptide clearance concern)
  • Not commercially available
  • Clinical trial participants only

Best Stacking Partners

MOTS-cHumaninEpitalon

Mechanism

TB-500 is a synthetic fragment of Thymosin Beta-4, a 43-amino acid protein that sequesters G-actin monomers, preventing premature polymerization and facilitating cellular migration and morphological changes essential for wound healing. It upregulates actin to promote cell migration, proliferation, and differentiation of stem/progenitor cells at injury sites. TB-500 also enhances angiogenesis, reduces inflammation, and promotes tissue remodeling through increased re-epithelialization and vascular density.

Standard Dosing

Research indicates 2-2.5 mg administered twice weekly via subcutaneous injection.

Timing

No strict timing requirements. Can be administered at any time of day. Systemic action means injection location is not critical.

Cycle Duration

Loading phase: 4-6 weeks. Total cycle: 8-16 weeks.

Side Effects

  • Temporary lethargy
  • Head rush upon injection
  • Injection site irritation
  • Mild headache

Contraindications

  • Active cancer (angiogenesis concern)
  • Pregnancy and breastfeeding
  • Recent myocardial infarction

Best Stacking Partners

BPC-157GHK-CuGH Secretagogues

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