How does LL-37 work?

LL-37 is the 37-building-block active form of cathelicidin, the only one of its kind people make. This site's profile says it breaks open the outer walls of germs and adjusts immune cells, wound repair, and inflammation. It is listed as leaving the body quickly (a short half-life). Its molecular weight is 4,493.3 daltons. The larger mid-stage study, in 148 people with leg ulcers, found no real improvement over a dummy treatment across everyone. A benefit showed up only when researchers looked back at a subgroup with large wounds, after the fact. An earlier first-in-people study, in 34 people with hard-to-heal leg ulcers from poor vein blood flow, found LL-37 on the skin at 0.5 mg/mL healed wounds about sixfold faster than a dummy treatment. The early sixfold result did not hold up. Reviews on that page describe it as a double-edged sword: it fights infection, and it is also tied to some inflammatory and autoimmune diseases. It is a research peptide, not an approved treatment. This FAQ does not invent a dose. Full record at /compounds/ll-37.

Educational use only. This database summarizes published research and is not medical advice. Where a dose appears it is a record of what a trial or clinic ran, or what people describe doing, with its source attached. Nothing here is a recommendation for personal use.

Part of healing and recovery peptides. BPC-157, TB-500, GHK-Cu, and the tissue repair family, including what actually has human data.