Human antimicrobial research peptide · Fact sheet
LL-37
Also known as Cathelicidin LL-37
LL-37 is a human host-defense peptide studied in wound formulations. A 148-person venous-ulcer trial did not improve healing overall; exploratory subgroup results do not establish a general wound or antimicrobial treatment.
What is LL-37?
LL-37 participates in innate immunity and inflammation as well as antimicrobial activity.
Topical wound formulations and systemic peptide exposure have different evidence and risks.
Benefits & claims
Interest includes ulcers, wound closure and infection-related biology. Activity against microbes in a laboratory does not establish treatment of human infections.
What the evidence supports
- In HEAL LL-37, the full study population had no significant healing advantage over placebo.
- An apparent advantage in larger ulcers came from a post hoc subgroup and needs prospective confirmation.
- These wound studies cannot support systemic antimicrobial, anti-aging or immune-boosting claims.
Research areas
- Venous leg ulcers
- Diabetic foot ulcers
- Innate immune signaling
Dosage & frequency
Human study contextHEAL LL-37 tested topical concentrations with compression therapy. These are trial formulation concentrations, not a systemic dosing schedule.
HEAL LL-37 phase 2b trial
148 patients with hard-to-heal venous leg ulcers receiving compression care
- Amount
- LL-37 solution at 0.5 or 1.6 mg/mL in separate arms
- Frequency
- Twice weekly during a 13-week randomized treatment phase
- Route studied or labeled
- Topical application to the study ulcer
Concentration alone does not specify a universal total dose; application depended on the wound protocol. The overall efficacy comparison was negative. The source contains full wound-care details.
How to read these amounts
An approved regimen belongs to a specific product, indication, and population. A study regimen describes what researchers tested; it does not establish a prescription or a safe self-use protocol. Products, routes, and formulations are not interchangeable. A prescriber uses the full label and individual clinical circumstances.
Personal accounts may describe amounts, schedules and outcomes beyond clinical research. They do not establish a regimen. Read the reported experiences
Formulations, interactions & practical context
- Identity and pharmacology
- LL-37 participates in innate immunity and inflammation as well as antimicrobial activity.
Formulation differences
- The study solution was applied to wounds with compression; it was not an injectable LL-37 regimen.
- Cream, solution and systemic preparations are not interchangeable.
Interactions & precautions
- The reviewed sources do not establish a comprehensive human interaction profile for this exact substance or combination.
What is still unresolved
- Reproducibility of the large-ulcer subgroup finding
- Long-term or systemic safety
- Clinical infection outcomes
Side effects & risks
- FDA notes possible immunogenicity and characterization issues and nonclinical concerns involving male reproduction and tumor promotion in some tissues.
- Tolerability of a topical trial formulation does not establish safety of systemic exposure.
This is a summary of the cited evidence, not a complete product label. A lack of human safety data does not establish safety.
Clinical research
Early human evidenceTopical human wound studies exist. The larger venous-ulcer study was negative overall; a smaller diabetic-foot-ulcer study reported improved granulation without demonstrating reduced bacterial colonization.
Studies
148-person phase 2b venous-ulcer trial; negative overall efficacy result.
Topical randomized study; wound granulation and bacterial findings.
Personal experiences
Reports describe what someone noticed. They cannot establish cause, typical results, or how often a side effect happens. Amounts and schedules describe the individual account, not an effective or safe dose. Product identity and strength may be unverified, and missing details are left explicit.
No attributable personal accounts were found in the sources reviewed.
Approval status
LL-37 has no FDA-approved therapeutic product. FDA identifies inadequate safety information and nonclinical reproductive and tumor-promoting concerns in certain settings.
Phase 2 research; no FDA-approved product
Approval covers the labeled product, use and population. A trial phase does not establish success; a stopped program is not ongoing research.
Open questions
- Reproducibility of the large-ulcer subgroup finding
- Long-term or systemic safety
- Clinical infection outcomes
Summary
These wound studies cannot support systemic antimicrobial, anti-aging or immune-boosting claims.
Sources
Medical evidence and regulatory sources are listed here. Personal reports are linked separately in the experiences section.
- pubmedHEAL LL-37 randomized trial
148-person phase 2b venous-ulcer trial; negative overall efficacy result.
- pubmedLL-37 cream in diabetic foot ulcers
Topical randomized study; wound granulation and bacterial findings.
- fdaFDA: safety concerns for nominated bulk substances
Ingredient-specific uncertainties; compounding consideration is separate from FDA drug approval.