LL-37 (Cathelicidin) vs TB-500 (Thymosin Beta-4)

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

✅ Stacking Partners — These compounds are commonly used together and may have synergistic effects.
LL-37 (Cathelicidin)TB-500 (Thymosin Beta-4)
CategoryPeptidesPeptides
Standard DoseResearch indicates 50-100 mcg daily via subcutaneous injection for immune support.Research indicates 2-2.5 mg administered twice weekly via subcutaneous injection.
TimingMorning administration preferred for immune support. Topical application directly to wound sites.No strict timing requirements. Can be administered at any time of day. Systemic action means injection location is not critical.
Cycle Duration4-8 week cycles. Short-term use preferred due to limited long-term safety data.Loading phase: 4-6 weeks. Total cycle: 8-16 weeks.
Evidence Levelanimal_plus_anecdotalanimal_plus_anecdotal

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

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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