LL-37 Research Peptide

Yes. Every batch of LL-37 is tested by an independent third-party laboratory using HPLC and MS-UPLC, confirming purity and mass identity before the batch is released. Pure Peptides does not test its own material.

Yes. The Certificate of Analysis for the batch currently in stock can be viewed and downloaded directly on this page, before you place an order. Each certificate states the batch number, the measured purity, and the date of analysis, and can be verified independently with the issuing laboratory using the report number it carries.

It means LL-37 is supplied for in-vitro laboratory research and for no other purpose, and must not be administered to humans or animals. LL-37 is legal to purchase in the United States for in vitro and non-clinical laboratory research. It has no FDA approval and no approved human use. LL-37 is not a scheduled substance under the Controlled Substances Act. Sold strictly for qualified research use, not human or veterinary administration.

LL-37 ships from US stock with cold-chain packaging and full tracking; orders placed before noon EST on business days are typically dispatched the same business day. On arrival, store the lyophilized powder at -20°C or below, dry and protected from light.

Yes, in four studies. Three were randomized placebo-controlled trials of a topical formulation: two in hard-to-heal venous leg ulcers and one in mildly infected diabetic foot ulcers. The first venous leg ulcer trial, in 34 patients, tested three concentrations, and the healing rate reached significance against placebo only at the lowest, with no difference at the highest. The second, a phase IIb trial in 148 patients testing the two lower concentrations, found no significant difference against placebo across the whole group, with a post hoc subgroup finding in patients whose wounds were largest. The diabetic foot ulcer trial reported a greater increase in granulation index with LL-37, and no significant difference between groups in the cytokines or the bacterial counts it measured. The fourth injected LL-37 directly into melanoma tumors in four people. Both venous leg ulcer trials described the formulation as safe and well tolerated. The phase IIb registry record nevertheless shows serious adverse events in 8.33% and 12.24% of the two LL-37 groups against 1.96% on placebo, from small numbers and with no deaths in any group. The LL-37 research article covers all four.

Not quite. Cathelicidin usually refers to hCAP18, the 18 kDa protein this peptide is cut from, and most of the published literature is indexed under that name. LL-37 is the 37-residue piece released from its C-terminal end. Research on the whole protein is not research on the fragment.

LL-37 is a human cathelicidin, a class of peptides defined by antimicrobial activity. One published in-vitro study reported minimum inhibitory concentrations below 10 micrograms per millilitre against several bacterial species, including vancomycin-resistant enterococci, with activity retained at 100 mM sodium chloride. That is a laboratory measurement against cultured organisms. It is not evidence about treating an infection, and this compound has no approved human use.