Peptide Graded

LL-37

Is LL-37 legal in the US?

No. It is not approved and is sold as a research chemical.

CAnimal and cell studiesNot approvedas of 2026-10-26

Not approved by the FDA for any use and sold as a research chemical. LL-37 was nominated for the FDA's compounding bulk-substances list and placed in Category 2 (significant safety risk); the nomination was withdrawn, the FDA removed it from the category in April 2026, and a Pharmacy Compounding Advisory Committee review is planned before the end of February 2027. 234

No. It has no approved form. The FDA listed it as a significant safety risk for compounding. The nomination was withdrawn in 2026. After that, the FDA removed it from that category pending an advisory committee review. That does not make it legal to compound or sell for human use. 234

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More on LL-37

Citations

  1. Biochem Biophys Res Commun 2020: LL-37 antiviral and immunomodulatory activity doi.org
  2. FDA: Certain bulk drug substances for use in compounding may present significant safety risks fda.gov
  3. FDA: Bulk drug substances nominated for use in compounding under section 503A, category list fda.gov
  4. FDA: Pharmacy Compounding Advisory Committee meetings fda.gov
  5. De Yang 2000, J Exp Med: LL-37 uses FPRL1 to chemoattract neutrophils, monocytes and T cells pubmed.ncbi.nlm.nih.gov
  6. Sorensen 2001, Blood: hCAP-18 is processed to LL-37 by proteinase 3 pubmed.ncbi.nlm.nih.gov
  7. Heilborn 2003, J Invest Dermatol: LL-37 in re-epithelialization of skin wounds and lacking in chronic ulcers pubmed.ncbi.nlm.nih.gov
  8. Salvado 2013, Arterioscler Thromb Vasc Biol: LL-37 induces angiogenesis via PGE2-EP3 signaling pubmed.ncbi.nlm.nih.gov
  9. Gombart 2005, FASEB J: CAMP gene is a direct target of the vitamin D receptor pubmed.ncbi.nlm.nih.gov
  10. Liu 2006, Science: Toll-like receptor triggering of a vitamin D-mediated antimicrobial response pubmed.ncbi.nlm.nih.gov
  11. 2025, Front Immunol: Post-translational modifications of the autoantigen LL37 in psoriasis pubmed.ncbi.nlm.nih.gov
  12. Lande 2007, Nature: Plasmacytoid dendritic cells sense self-DNA coupled with antimicrobial peptide pubmed.ncbi.nlm.nih.gov
  13. Yamasaki 2007, Nat Med: Serine protease activity and cathelicidin promote skin inflammation in rosacea pubmed.ncbi.nlm.nih.gov
  14. De Smet 2005, Biotechnol Lett: Human antimicrobial peptides, defensins, cathelicidins and histatins pubmed.ncbi.nlm.nih.gov
  15. Gronberg 2021, Wound Repair Regen: LL-37 in hard-to-heal venous leg ulcers, randomized placebo-controlled trial pubmed.ncbi.nlm.nih.gov
  16. 2023, Arch Dermatol Res: LL-37 cream in diabetic foot ulcer, randomized double-blind controlled trial pubmed.ncbi.nlm.nih.gov

Reference information only, not medical advice. Drawn from the LL-37 article, fact-checked against the cited sources. No dosing anywhere on this site.