What is the recommended LL-37 dosage?

LL-37 dosing varies by experience level. Beginners typically start at 50mcg 2x/week, moderate users at 100mcg 2x/week, and aggressive protocols use 200mcg 3x/week.

How do you reconstitute LL-37?

LL-37 typically comes in 5mg vials. Add 2mL of bacteriostatic water to the vial. Use our free calculator for exact syringe units based on your desired dose.

What is the half-life of LL-37?

The half-life of LL-37 is ~4-6 hours. This determines how frequently you need to dose for consistent blood levels.

LL-37

ImmuneInjectionPreclinicalGrade B~4-6 hours half-life

Antimicrobial PeptideBiofilm DisruptionInnate ImmunityWound HealingCathelicidin

Benefits

Broad-spectrum antimicrobial: bacteria, viruses, fungi

Breaks down bacterial biofilms

Enhances innate immune defense

Promotes wound healing

Modulates inflammatory response

Half-Life

~4-6 hours

Route

Injection

Frequency

2x/week

Vial Sizes

5mg

BAC Water

2mL

Safety Grade

Grade B

Open LL-37 Dosage Calculator

Calculate exact syringe units for your vial and dose

About LL-37

LL-37 is the only human cathelicidin antimicrobial peptide, naturally produced by immune cells, epithelial cells, and barrier tissues. It's a 37-amino-acid peptide that forms the body's first line of innate immune defense. It directly kills bacteria, viruses, and fungi by disrupting their membranes, and is uniquely effective at breaking down biofilms — the protective structures bacteria form in chronic infections. It also modulates the immune response and promotes wound healing.

Who Should Consider LL-37

Individuals with chronic or recurrent bacterial infections
Patients with biofilm-associated infections (chronic wounds, implant infections)
Those with slow-healing or non-healing wounds
People with compromised innate immune function
Individuals recovering from skin injuries or surgical wounds

How LL-37 Works

LL-37 is a 37-amino-acid cationic peptide cleaved from the precursor protein hCAP-18 by proteinase 3 in neutrophil granules. Its amphipathic alpha-helical structure allows it to interact with negatively charged bacterial membranes through electrostatic attraction. Once bound, the hydrophobic face of LL-37 inserts into the lipid bilayer, forming toroidal pores or disrupting membrane integrity through a carpet-like mechanism, leading to rapid bacterial lysis. Against biofilms, LL-37 penetrates the extracellular polymeric matrix, disrupts bacterial communication (quorum sensing), and kills embedded bacteria that are otherwise resistant to conventional antibiotics. Beyond direct antimicrobial killing, LL-37 binds and neutralizes lipopolysaccharide (LPS) and lipoteichoic acid, preventing excessive inflammatory signaling from bacterial endotoxins. It acts as a chemoattractant for neutrophils, monocytes, and T-cells through formyl peptide receptor-like 1 (FPRL1) activation, recruiting immune cells to sites of infection or injury. LL-37 also stimulates wound healing by promoting angiogenesis through VEGF upregulation, enhancing keratinocyte and epithelial cell migration, and increasing collagen deposition. At low concentrations, it suppresses pro-inflammatory cytokine release from macrophages, while at higher concentrations it can amplify inflammatory responses — making dose selection important for therapeutic applications.

What to Expect

Days 1-3

Treatment initiation. LL-37 begins circulating and interacting with target tissues. Injection site redness or mild soreness is common at this stage. No noticeable systemic changes yet.

Days 4-10

Early immune activation. Innate immune cell recruitment increases at infection or wound sites. Some users report reduced redness or drainage from chronic wounds. Mild flu-like symptoms may occur as immune activity ramps up.

Weeks 2-3

Antimicrobial and wound-healing effects become more apparent. Biofilm disruption allows better immune clearance of chronic infections. Wound granulation tissue formation and re-epithelialization may accelerate.

Weeks 4-6

Peak therapeutic window. Measurable improvements in wound closure, reduced bacterial load at infection sites, and stronger innate immune markers. Cycle typically ends here — reassess before continuing.

Dosing Protocol

Level	Dose / Injection	Frequency
Beginner	50mcg	2x/week
Moderate	100mcg	2x/week
Aggressive	200mcg	3x/week

Note: Human cathelicidin antimicrobial peptide. Very potent — use low doses. Broad-spectrum antimicrobial activity against bacteria, viruses, fungi, and biofilms. Cycle 4-6 weeks. Monitor for injection site reactions.

Pharmacokinetics

Half-Life

Bioavailability

SC: not formally established; rapid local absorption expected

Tmax

~1-2 hours (SC, estimated)

Data Confidence

low

Source: Estimated 4-6 hours based on proteolytic degradation kinetics in serum and wound fluid (PMID 21547341)

Pharmacokinetics — Active Dose Over Time

Loading the interactive decay curve.

Side Effects

Injection site pain and redness (common at higher doses). Transient flu-like symptoms. Use low doses — LL-37 is very potent. Rare: allergic reaction.

Contraindications

Pregnancy or breastfeeding — no safety data available in these populations
Known hypersensitivity to LL-37 or cathelicidin-derived peptides
Active autoimmune conditions (psoriasis, lupus) — LL-37 is elevated in psoriatic lesions and may worsen flares
Active malignancy — LL-37 has mixed effects on tumor cells and may promote angiogenesis
Children under 18 — not studied in pediatric populations

Drug Interactions

Immunosuppressants (corticosteroids, cyclosporine, methotrexate) — may blunt LL-37 immune-stimulating effects
Other antimicrobial peptides or immune-stimulating peptides (Thymosin Alpha-1, KPV) — additive immune activation; use caution with stacking
Anticoagulants (warfarin, heparin) — LL-37 may interact with heparin-binding sites; monitor coagulation parameters
Topical antimicrobials — potential additive effects when LL-37 is used alongside wound care agents