LL-37 is the only human cathelicidin, a 37-residue antimicrobial peptide made by skin, gut and airway cells and by several types of white blood cell.
A 2006 review in Biochimica et Biophysica Acta describes LL-37 as an amphipathic, helical peptide with broad antimicrobial activity (Dürr et al., 2006). Beyond killing microbes, it regulates inflammation, draws immune cells to wound and infection sites, neutralizes bacterial lipopolysaccharide and promotes wound closure. Those wound-healing roles explain why drug developers tested it on chronic skin ulcers.
Human evidence is limited to topical use on venous leg ulcers. A 34-patient first-in-human trial reported faster healing at the two lower concentrations tested (Wound Repair and Regeneration, 2014). The larger phase IIb HEAL LL-37 trial, with 148 patients, found no significant healing improvement over placebo in the full study population; a benefit appeared only in a post hoc subgroup with large wounds (Mahlapuu et al., 2021). The developer, Promore Pharma, uses the name ropocamptide. Both trials applied LL-37 to the wound, not by injection.
No. LL-37 has no FDA approval for any use, and FDA has stated it lacks enough safety information to know whether it would harm people.
FDA placed cathelicidin LL-37 in Category 2 of its interim policy for 503A pharmacy compounding, the group with significant safety risks. Its summary cites possible immunogenicity, peptide-related impurities, nonclinical findings that suggest harm to male reproduction, and evidence that LL-37 can promote tumor growth in some tissues (FDA). The nominators withdrew the nomination, and FDA’s May 2026 list does not place LL-37 in any of its three categories (FDA 503A categories).
For LL-37, a batch result answers a question that matters more than usual. FDA’s concerns include impurities created during synthesis, and the agency says it cannot judge the safety of LL-37 given to people. A vial that tests at the wrong identity or low purity adds a second unknown on top of the first.
Before trusting any LL-37 label, check that batch’s published result in our latest tests or in Janoshik's public results database. No results are published for LL-37 yet in our index. When the first published result arrives, a vendor leaderboard appears above.