Tissue Repair & HealingModerate Evidence

LL-37 Peptide Therapy

Benefits, Side Effects, Cost & Protocols

LL-37 peptide molecular structure diagram from PubChem

LL-37 (cathelicidin) is a 37-amino acid antimicrobial peptide encoded by the CAMP gene in humans. It is the active form of the precursor CAP-18, processed by proteinase 3-mediated cleavage. It plays key roles in innate immune defense against bacterial, viral, and fungal infections.

ByChris Riley(CFA)&Alex Evans, PharmD, MBA(PharmD, MBA)|Updated May 19, 2026

Clinically Reviewed

Reviewed by Alex Evans, PharmD, MBA · Updated May 2026

Evidence-Based

Sourced from FDA, PubMed & ClinicalTrials.gov · View sources

FDA Status

Banned from Compounding March 2024 Not eligible for compounding. Antimicrobial peptide removed from nomination list.

Evidence

Moderate Evidence

Who Is LL-37 Best For?

Wound healingAntimicrobial activityImmune modulationLimited human trials or strong preclinical

How LL-37 Works

Human cathelicidin that exhibits broad-spectrum antimicrobial activity while promoting wound healing and immune response.

LL-37 FAQ

What is LL-37?

LL-37 is a naturally occurring antimicrobial peptide (cathelicidin) researched for wound healing, antimicrobial activity, and immune modulation.

How does LL-37 work?

Human cathelicidin that exhibits broad-spectrum antimicrobial activity while promoting wound healing and immune response.

Is LL-37 legal to buy?

LL-37 is sold as a research chemical for laboratory use only. It is not approved for human use by the FDA. Regulations vary by jurisdiction.

Where can I buy LL-37?

LL-37 is available as a research compound from verified online vendors. Always verify third-party testing before purchasing.

What category does LL-37 belong to?

LL-37 is primarily classified as a tissue repair & healing peptide. Peptides studied for their potential in wound healing, tendon/ligament repair, gut healing, and general tissue regeneration.

What are the research benefits of LL-37?

LL-37 has been studied for: Wound healing, Antimicrobial activity, Immune modulation. Wound healing + antimicrobial; human defensin peptide.

Key Studies

2,472 total on PubMed1,801 human trials

Efficacy and safety of Oral LL-37 against the Omicron BA.5.1.3 variant of SARS-COV-2: A randomized trial

Zhao Y, Zhang H, Zhao Z et al

J Med VirolPhase 2

Oral LL-37 demonstrated efficacy and safety against Omicron BA.5.1.3 SARS-CoV-2 variant

The therapeutic efficacy of Bifidobacterium animalis subsp. lactis BB-12(®) in infant colic: A randomised, double blind, placebo-controlled trial

Nocerino R, De Filippis F, Cecere G et al

Aliment Pharmacol Ther · Aliment Pharmacol TherRCT

Bifidobacterium animalis BB-12 showed therapeutic efficacy in infant colic

Treatment with LL-37 is safe and effective in enhancing healing of hard-to-heal venous leg ulcers: a randomized, placebo-controlled clinical trial

Grönberg A, Mahlapuu M, Ståhle M et al

Wound Repair Regen · Wound Repair RegenPhase 2

LL-37 treatment is safe and effective in enhancing healing of hard-to-heal venous leg ulcers

Serum LL-37 and inflammatory cytokines levels in psoriasis

LL-37 Compound Data

Molecular Formula

C205H340N60O53

Molecular Weight

4493 g/mol

IUPAC Name

(4S)-5-[[(1S)-5-amino-1-[[(1S,2S)-1-[[2-[[(1S)-5-amino-1-[[(1S)-1-[[(1S)-2-[[(1S)-5-amino-1-[[(1S)-1-[[(1S,2S)-1-[[(1S)-1-[[(1S)-4-amino-1-[[(1S)-1-[[(1S,2S)-1-[[(1S)-5-amino-1-[[(1S)-2-[[(1S)-2-[[(1S)-1-[[(1S)-1-[[(1S)-3-amino-1-[[(1S)-1-[[(1S)-1-[(2S)-2-[[(1S)-1-[[(1S,2R)-1-[[(1S)-3-carboxy-1-[[(1S)-1-carboxy-2-hydroxy-ethyl]carbamoyl]propyl]carbamoyl]-2-hydroxy-propyl]carbamoyl]-4-guanidino-butyl]carbamoyl]pyrrolidine-1-carbonyl]-2-methyl-propyl]carbamoyl]-3-methyl-butyl]carbamoyl]-3-oxo-propyl]carbamoyl]-4-guanidino-butyl]carbamoyl]-3-methyl-butyl]amino]-1-benzyl-2-oxo-ethyl]amino]-1-(carboxymethyl)-2-oxo-ethyl]carbamoyl]pentyl]carbamoyl]-2-methyl-butyl]carbamoyl]-4-guanidino-butyl]carbamoyl]-4-oxo-butyl]carbamoyl]-2-methyl-propyl]carbamoyl]-2-methyl-butyl]carbamoyl]-4-guanidino-butyl]carbamoyl]pentyl]amino]-1-benzyl-2-oxo-ethyl]carbamoyl]-3-carboxy-propyl]carbamoyl]pentyl]amino]-2-oxo-ethyl]carbamoyl]-2-methyl-butyl]carbamoyl]pentyl]amino]-4-[[(2S)-6-amino-2-[[(2S)-2-[[(2S)-6-amino-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[2-[[(2S)-2-[[(2S)-2-amino-4-methyl-pentanoyl]amino]-4-methyl-pentanoyl]amino]acetyl]amino]-3-carboxy-propanoyl]amino]-3-phenyl-propanoyl]amino]-3-phenyl-propanoyl]amino]-5-guanidino-pentanoyl]amino]hexanoyl]amino]-3-hydroxy-propanoyl]amino]hexanoyl]amino]-5-oxo-pentanoic acid

View full compound on PubChem

LL-37 News

Antimicrobial proteins and peptides in pregnancy: Guardians of the maternal–fetal frontier - Frontiers

Frontiers · 5 days ago

Biophysical and transcriptomic characterization of LL-37-derived antimicrobial peptide targeting multidrug-resistant Escherichia coli and ESKAPE pathogens | Scientific Reports - Nature

Nature · 7 months ago

Bacteriocin-transport–inspired oral peptide-probiotic delivery ameliorates IBD complications via autophagy and gut homeostasis - Science | AAAS

Science | AAAS · 4 months ago

Development of nanobody-conjugated LL37 for synergistic therapy against MDR Acinetobacter baumannii - ASM Journals

ASM Journals · 3 months ago

Cathelicidin LL37-loaded extracellular vesicles from Edwardsiella piscicida promote antibacterial and wound-healing activity - Nature

Nature · 5 months ago

News aggregated via Google News. Inclusion does not imply endorsement.

Medical Disclaimer: The information on this page is for educational purposes only and does not constitute medical advice. Peptide therapies have not been evaluated by the FDA for most listed indications.All prices shown are estimates based on publicly available data and may not reflect current pricing — providers and brands set their own prices and can change them at any time. Always verify pricing directly with the provider before purchasing. Consult a licensed healthcare provider before starting any peptide protocol.

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