LL-37 is the human cathelicidin antimicrobial peptide, reported to disrupt microbial membranes and modulate immune responses in antimicrobial, anti-biofilm, and wound-healing roles. Most evidence stays preclinical with minimal human data, and it holds no FDA approval. Below you'll find reported dosing, reconstitution, safety, and legal status. Educational only, not medical advice.
A human cathelicidin antimicrobial peptide that disrupts microbial membranes and modulates immune responses (antimicrobial, anti-biofilm, and wound-healing roles reported).
Half-life
Uncertain; limited reliable human PK data for therapeutic use. Treat as unknown.
Regulatory status
Not FDA-approved. Was on FDA Category 2; per April 2026 reporting slated for removal from Category 2, with PCAC review anticipated late 2026 to early 2027 (compounding reconsideration only). Research chemical / gray-market.
Safety
Limited human safety data. As an immune-active peptide, theoretical pro-inflammatory effects and roles in some autoimmune/inflammatory conditions noted in research. Long-term safety unknown.
Evidence
Mostly preclinical/laboratory research; minimal human therapeutic data.
Sources
Durr UH, Sudheendra US, Ramamoorthy A. LL-37, the only human member of the cathelicidin family of antimicrobial peptides. Biochimica et Biophysica Acta. 2006;1758(9):1408-1425. https://pubmed.ncbi.nlm.nih.gov/16716248/
Gronberg A, Mahlapuu M, Stahle M, Whately-Smith C, Heilborn JD. Treatment with LL-37 is safe and effective in enhancing healing of hard-to-heal venous leg ulcers: a randomized, placebo-controlled clinical trial. Wound Repair and Regeneration. 2014;22(5):613-621. https://pubmed.ncbi.nlm.nih.gov/25041740/
Pukkapote S, et al. Efficacy of LL-37 cream in enhancing healing of diabetic foot ulcer: a randomized double-blind controlled trial. Archives of Dermatological Research. 2023;315(9):2625-2633. https://pubmed.ncbi.nlm.nih.gov/37480520/
Ridyard KE, Overhage J. The Potential of Human Peptide LL-37 as an Antimicrobial and Anti-Biofilm Agent. Antibiotics (Basel). 2021;10(6):650. https://pubmed.ncbi.nlm.nih.gov/34071318/
Dean SN, Bishop BM, van Hoek ML. Natural and synthetic cathelicidin peptides with antimicrobial and antibiofilm activity against Staphylococcus aureus. BMC Microbiology. 2011;11:114. https://pubmed.ncbi.nlm.nih.gov/21605457/
Overhage J, Campisano A, Bains M, Torfs EC, Rehm BH, Hancock RE. Human host defense peptide LL-37 prevents bacterial biofilm formation. Infection and Immunity. 2008;76(9):4176-4182. https://pubmed.ncbi.nlm.nih.gov/18591225/
Liu PT, Stenger S, Li H, et al. Toll-like receptor triggering of a vitamin D-mediated human antimicrobial response. Science. 2006;311(5768):1770-1773. https://pubmed.ncbi.nlm.nih.gov/16497887/
Sorensen OE, Follin P, Johnsen AH, et al. Human cathelicidin, hCAP-18, is processed to the antimicrobial peptide LL-37 by extracellular cleavage with proteinase 3. Blood. 2001;97(12):3951-3959. https://pubmed.ncbi.nlm.nih.gov/11389039/
PepWise is an informational and educational tracking tool, not medical advice and not a medical device. LL-37 may be experimental, restricted, or prescription-only; many research peptides are not FDA-approved. Consult a licensed healthcare provider before starting, changing, or stopping any protocol. Operated by STC Consulting, Inc.
