Defense peptide made by the body itself to fight bacteria and help healing. Tested in an ointment for venous leg ulcers, with mixed results.
Regulatory status
In clinical trials
Family
Human antimicrobial peptide (cathelicidin)
Scientific evidence
Low-moderate
Number of findings
2
Where it acts
Immunity and defense · Skin and aging
Also known as
LL-37, human cathelicidin, cathelicidin, hCAP18
Regulatory status
FDA (US): Not approved. The FDA warns of insufficient safety data and of animal findings regarding male reproduction and a possible tumor-promoting effect.
EMA (EU): Not approved
Dose
In trials, topical application on the ulcer of 0.5 or 1.6 mg/mL twice a week (Grönberg 2014; Mahlapuu 2021). There is no approved regimen, nor for injectable use.
Safety
Topical: well tolerated in trials. Injectable use: no human safety data; the FDA cites preclinical findings of male reproductive harm and possible tumor promotion. Its use only makes sense in research or under medical supervision; buying it is not recommended.
Differences between women and men
The FDA mentions preclinical findings of harmful effects on male reproduction.
Effect by goal · level of evidence
Venous leg ulcers (phase 1/2)
improvesLow-moderateRCT (AA)in people
−68% area
34 patients, 4 weeks: with 0.5 mg/mL the healing rate was about 6 times greater than with placebo and ulcer area fell by 68%. The highest dose (3.2 mg/mL) did not work.
148 patients, 13 weeks: overall, healing did not improve vs placebo. Only a post hoc analysis in large ulcers (≥10 cm²) suggested benefit. It was safe and well tolerated.
Disrupts the membranes of bacteria, fungi, and some viruses. It also attracts immune cells, modulates inflammation, and stimulates blood vessel formation and skin repair.
What the evidence says
In people
Venous leg ulcers (phase 1/2). 34 patients, 4 weeks: with 0.5 mg/mL the healing rate was about 6 times higher than with placebo and the ulcer area fell by 68%. The highest dose (3.2 mg/mL) did not work. PubMed 25041740
Venous leg ulcers (phase 2b). 148 patients, 13 weeks: overall, healing did not improve compared with placebo. Only a later analysis in large ulcers (≥10 cm²) suggested benefit. It was safe and well tolerated. PubMed 34687253