LL-37 (Cathelicidin) vs SS-31 (Elamipretide)

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

LL-37 (Cathelicidin)SS-31 (Elamipretide)
CategoryPeptidesPeptides
Standard DoseResearch indicates 50-100 mcg daily via subcutaneous injection for immune support.Research indicates 0.05-0.25 mg/kg daily via subcutaneous injection. Clinical trials used 4-40 mg/day IV or SC.
TimingMorning administration preferred for immune support. Topical application directly to wound sites.Morning dosing preferred. No food timing restrictions.
Cycle Duration4-8 week cycles. Short-term use preferred due to limited long-term safety data.Clinical trials ranged from single dose to 48 weeks. Optimal cycle length not established.
Evidence Levelanimal_plus_anecdotalEmerging (Phase 2/3 trials)

Mechanism

LL-37 is a 37-residue amphipathic helical antimicrobial peptide, the only human cathelicidin, that kills bacteria by forming tetrameric channels that perforate cytoplasmic membranes. Beyond direct antimicrobial activity, it modulates innate immunity through formyl-peptide receptor 2 (FPR2), induces chemotaxis of neutrophils and monocytes, upregulates CXCR4 and IL-8, and neutralizes bacterial endotoxins (LPS). It also promotes wound healing through keratinocyte migration and angiogenesis.

Standard Dosing

Research indicates 50-100 mcg daily via subcutaneous injection for immune support.

Timing

Morning administration preferred for immune support. Topical application directly to wound sites.

Cycle Duration

4-8 week cycles. Short-term use preferred due to limited long-term safety data.

Side Effects

  • Injection site pain and redness
  • Localized inflammation
  • Potential mast cell activation

Contraindications

  • Active autoimmune conditions (particularly lupus — LL-37 is implicated in SLE pathophysiology)
  • Pregnancy and breastfeeding
  • Psoriasis (may exacerbate)

Best Stacking Partners

KPVThymosin Alpha-1BPC-157

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

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