LL-37 Dosage Chart: 125mcg/Day for 50 Days

LL-37 is the only human cathelicidin antimicrobial peptide — a 37-amino-acid peptide with broad-spectrum antimicrobial activity and potent immune-modulating properties. No human clinical trials exist for injectable LL-37. This is not medical advice.

Research-context information only. LL-37 is a research peptide. Protocols, doses, and reactions reported below come from published research and self-reported community sources. This article reports what has been documented, not what should be done. Consult a licensed physician for personal medical decisions.

Quick Reference: Standard Protocol

Cycling Details

The standard protocol runs approximately 50 days of continuous daily injections, followed by 4 weeks off. One 5 mg vial at 125 mcg/day provides 40 doses — most users purchase 2 vials per cycle to cover the full 50 days.

The washout period allows the immune system to return to baseline and prevents potential desensitization. Some community members use an acute protocol (125-200 mcg daily for 2-4 weeks) during active immune challenges, while the full 50-day cycle serves as preventive/maintenance use.

Vitamin D3 synergy: Community protocols commonly include Vitamin D3 (5,000-10,000 IU daily) because Vitamin D directly upregulates endogenous LL-37 production via the VDRE in the cathelicidin gene (Liu et al., 2006). Community protocols target a serum 25(OH)D of 50-80 ng/mL. Many add Vitamin K2 (100-200 mcg MK-7) alongside high-dose D3.

Enhanced Protocol (Community)

Some community protocols describe 200 mcg daily for 6-8 weeks as an enhanced option, though the 125 mcg starting point is more consistently reported. This uses 8 units per injection instead of 5.

Routes of Administration

Subcutaneous (standard): Abdomen, love handles, or thighs. Protocols describe rotating injection sites. Morning injection is the most common community timing, aligning with immune circadian rhythms. Absorption is not affected by meals.

Reconstitution Quick Reference

Math: 5,000 mcg / 2 mL = 2,500 mcg/mL. 125 mcg / 2,500 = 0.05 mL = 5 units. One vial provides 40 doses (40 days). Community technique describes gentle swirling rather than shaking; documented storage is refrigeration, with use within 28 days.

For step-by-step reconstitution instructions, see the BPC-157 reconstitution guide — same technique applies.

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Where These Numbers Come From

LL-37 dosing is entirely community-derived. No pharmacokinetic studies exist for subcutaneous injection in humans.

LL-37 demonstrates antimicrobial activity against a broad range of pathogens, disrupting bacterial membranes through electrostatic interactions (Dürr et al., 2006). LL-37 expression is directly regulated by Vitamin D through the VDRE in the cathelicidin gene promoter, with TLR activation upregulating the vitamin D receptor and the 1-hydroxylase that converts 25(OH)D to active 1,25(OH)₂D (Liu et al., 2006).

LL-37 also disrupts and prevents bacterial biofilm formation at sub-MIC concentrations (Overhage et al., 2008). Beyond direct killing, LL-37 recruits immune cells and modulates inflammatory pathways (Kahlenberg & Kaplan, 2013).

The 125 mcg daily dose appears to be a conservative starting point extrapolated from in vitro effective concentrations, natural production rates, practical vial math (5 mg vial = 40 doses at 125 mcg), and community tolerance reports.

Stacking Protocols

Community protocols describe starting one peptide at a time to assess tolerance, using different injection sites when combining, and aligning cycle lengths for simplicity.

Side Effects & Safety

• Injection site redness/stinging — most commonly reported, typically mild
• Transient warmth or swelling at injection site
• Mild flu-like symptoms — first 1-3 days, possible immune activation response
• Herxheimer-like reactions — reported by some, possibly from microbial die-off
• Autoimmune caution — LL-37 overexpression is associated with psoriasis and rosacea; community protocols note elevated caution is warranted for these conditions, given LL-37's role in psoriasis and rosacea pathogenesis (Morizane & Gallo, 2012)
• No human clinical safety data for injectable LL-37
• Pregnancy/nursing — no safety data exists; community protocols exclude pregnant or nursing individuals

mg to Units Conversion

On a standard 100-unit insulin syringe, each "unit" equals 0.01 mL (so 100 units = 1 mL). Once LL-37 is reconstituted, the conversion from a target dose to syringe units depends on the chosen dilution.

The two reconstitution ratios most often described in community protocols are below.

Reconstitution A: 5 mg vial + 2 mL BAC water (2.5 mg/mL) — the standard dilution from the Quick Reference above.

Reconstitution B: 5 mg vial + 5 mL BAC water (1 mg/mL) — more BAC water for larger, easier-to-measure draws.

These conversions reflect the dilutions documented in community reconstitution protocols. They report how the math is described, not a recommended dosing schedule.