LL-37 Dosage Guide, Benefits & Side Effects

There is no clinically validated injectable dosing protocol for LL-37 in humans. The strongest human evidence comes from topical wound-care trials using gel concentrations of 0.5 mg/mL and 1.6 mg/mL applied to venous leg ulcers, not from injections. In research and biohacking communities, subcutaneous protocols circulating online typically describe 100-200 mcg per day (sometimes split into two 50-100 mcg doses), used 5 days a week for 2-6 weeks followed by a break, but these regimens are anecdotal and have not been validated in peer-reviewed human trials. Animal studies used doses (up to 1-5 mg/kg) that do not translate directly to human dosing.

LL-37 is typically supplied as a lyophilized (freeze-dried) powder. Lyophilized peptide is generally stable for months when kept sealed, desiccated, and stored at or below -18 to -20°C (room temperature storage for short periods is sometimes tolerated but shortens shelf life). It is commonly reconstituted with bacteriostatic or sterile water by slowly injecting the liquid down the inside wall of the vial to avoid foaming/denaturation, then left to dissolve without shaking. Once reconstituted, it is generally recommended to store the solution refrigerated (about 2-8°C) and use it within roughly 28-30 days, avoiding light exposure, heat, and repeated freeze-thaw cycles.

In controlled topical wound-healing trials, LL-37 has shown a generally favorable safety profile with few adverse events attributed to treatment. However, laboratory studies show LL-37 can be cytotoxic to human cells at higher concentrations (roughly 1-10 micromolar range), and it is notably elevated in inflammatory skin conditions such as psoriasis and rosacea, raising questions about its role in inflammatory disease. There is essentially no controlled human safety data for injectable or systemic use, so risks of that route (site reactions, immune effects, unknown long-term effects) are not well characterized. Anyone considering use should be aware these products are not evaluated by regulators for human administration.