Supplement Scholar
Antimicrobial

LL-37

Research compound. This is not a dietary supplement. Unless it is identified as an approved prescription drug, it is not approved by the FDA for human use. This page summarizes published research for education only; we do not sell it or link to sellers.

LL-37. The body's endogenous antimicrobial peptide, with immunomodulatory and wound-healing roles.

How it works. Disrupts bacterial membranes directly while also modulating host immune signaling, chemotaxis, and wound-healing pathways.

What the research supports. 2 graded claims. Strongest: Activity against resistant organisms in research (preclinical).

Hormonal impact. Effects on Vitamin D-dependent transcription, Inflammatory cytokines.

Side effects and interactions. 0 medication interactions listed. Serious: Pro-inflammatory if dosed inappropriately.

Stacking. Pairs well with Adequate vitamin D status. Avoid combining with Autoimmune skin disease flares.

Common forms. Available as Topical, Subcutaneous injection (research).

Community. Experiences from people who have tried LL-37. Anecdotes are not medical advice.

LL-37. The body's endogenous antimicrobial peptide, with immunomodulatory and wound-healing roles.

37-residue chainC205H340N60O53 · 4493 g/mol

What it is

LL-37 is the active fragment of human cathelicidin (hCAP-18), produced by neutrophils and epithelial cells as part of innate immunity.

Also called

Cathelicidin

How it works

Disrupts bacterial membranes directly while also modulating host immune signaling, chemotaxis, and wound-healing pathways.

Pathways

  • Bacterial membrane disruption
  • Chemotaxis (FPR2)
  • Wound-healing signaling

Effects

  • ⊘Broad-spectrum bacterial activity inhibits
  • +Wound re-epithelialization supports
  • +Innate immune recruitment supports

What the research supports

Activity against resistant organisms in researchpreclinical
Combined antimicrobial and pro-healing effectspreclinical

Strong: consistent results across large trials or meta-analyses. Moderate: several trials, mostly positive. Limited: small or mixed studies. Preclinical: animal or cell research only.

Hormonal impact

~Vitamin D-dependent transcriptionmodulates
~Inflammatory cytokinesmodulates

Side effects & interactions

Common side effects

  • Local irritation at site of application

Serious

  • Pro-inflammatory if dosed inappropriately

No notable medication interactions listed.

Check any supplement–medication combination with your pharmacist before starting.

Combines with

Pairs well

  • Adequate vitamin D statusVitamin D regulates endogenous expression.

Avoid combining

  • Autoimmune skin disease flaresMay amplify ongoing inflammation.

Common forms

  • Topical
  • Subcutaneous injection (research)

Discussion

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