LL-37 (Cathelicidin) vs Sermorelin

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

LL-37 (Cathelicidin)Sermorelin
CategoryPeptidesPeptides
Standard DoseResearch indicates 50-100 mcg daily via subcutaneous injection for immune support.Research indicates 200-300 mcg administered once daily at bedtime via subcutaneous injection.
TimingMorning administration preferred for immune support. Topical application directly to wound sites.Bedtime administration (aligns with natural nocturnal GH release). On empty stomach.
Cycle Duration4-8 week cycles. Short-term use preferred due to limited long-term safety data.12-24 week cycles. Some protocols use continuous treatment.
Evidence Levelanimal_plus_anecdotalstrong_human

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
B

Sermorelin

Peptides

Mechanism

Sermorelin is a synthetic 29-amino acid peptide representing the biologically active fragment of GHRH (amino acids 1-29) with full functional activity. It activates GHRH receptors on pituitary somatotrophs, stimulating cAMP production via Gs protein/adenylate cyclase and MAP kinase pathways. Due to the interactive effects of sermorelin and endogenous somatostatin, GH release is episodic rather than continuous. Sermorelin also stimulates pituitary gene transcription of GH mRNA, increasing and preserving pituitary GH reserve.

Standard Dosing

Research indicates 200-300 mcg administered once daily at bedtime via subcutaneous injection.

Timing

Bedtime administration (aligns with natural nocturnal GH release). On empty stomach.

Cycle Duration

12-24 week cycles. Some protocols use continuous treatment.

Side Effects

  • Injection site reactions
  • Facial flushing
  • Headache
  • Dizziness
  • Transient taste changes

Contraindications

  • Active cancer
  • Pregnancy and breastfeeding
  • Intracranial hypertension

Best Stacking Partners

IpamorelinGHRP-2GHRP-6

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