Peptides
LL-37: antimicrobial biology and the wound-healing trials
How does it work?
LL-37 is the active human cathelicidin peptide. It can affect microbes and immune-cell signaling in laboratory systems, which prompted investigation as a wound treatment. Biological activity does not by itself establish an infection treatment or a healing benefit in people. [1]
What do trials show?
A multicenter randomized trial assigned 148 people with hard-to-heal venous leg ulcers to topical LL-37 or placebo in addition to compression therapy. In the full study population, neither 0.5 nor 1.6 mg/mL LL-37 significantly improved the prespecified healing outcome. A post-hoc signal in people with larger wounds needs confirmation in a trial designed for that group. The tested product was applied to ulcers, not injected as a research vial. [1]
Safety
The topical trial cannot define the risks of systemic or injectable LL-37. FDA says compounded LL-37 may carry immunogenicity and impurity risks and lacks sufficient human safety information for proposed uses; nonclinical work raises additional concerns in some tissues. Those warnings do not mean a particular harm has been proved in patients, but they make an unverified injection protocol especially uncertain. [2]
DOSE STATUS
How much?
EVIDENCE CONTEXT
Why?
The cited evidence does not establish a dose for this use or product.
For research context, investigators applied topical solutions of 0.5 or 1.6 mg/mL twice weekly along with compression therapy for 13 weeks. Neither concentration produced a significant overall healing benefit, and a topical concentration is not an injectable dose. No established safe/effective self-use dose or trustworthy exact-product anecdotal dose was identified. [1]