LL-37 Cycle Guide

What Is LL-37 and Why Does Dosing Matter?

LL-37 (Human cathelicidin antimicrobial peptide LL-37) is a Antimicrobial peptide, host defense peptide. Endogenous human antimicrobial peptide; the only human member of the cathelicidin family; produced by neutrophils, macrophages, and epithelial cells. Getting the dosage right is critical — too little may produce no measurable effect, while excessive amounts increase risk without proportional benefit.

The standard research dosage for LL-37 has been established through preclinical studies and community protocols. This guide covers the evidence-backed dosing range, timing, and cycle structure.

What Is the Recommended LL-37 Dosage?

The most widely used LL-37 dosage is 100-500 mcg (topical/local application), administered topical or local application as needed via topical wound application, local injection, intranasal.

Beginners should start at the lower end of this range and titrate upward only if needed. The half-life of LL-37 is rapidly degraded by proteases; major clinical limitation, which directly determines how often you need to dose to maintain stable blood levels.

For LL-37 specifically, the acute use as needed cycle length is standard. Longer isn't always better — Antimicrobial peptide, host defense peptide compounds require cycling to maintain receptor sensitivity.

When Should You Dose LL-37?

With a half-life of rapidly degraded by proteases; major clinical limitation, timing your LL-37 administration affects peak blood levels. Most protocols call for topical or local application as needed.

For peptides administered before bed (common with GH-related compounds), the goal is to amplify the natural nocturnal growth hormone pulse. For healing peptides, proximity to the injury site via local injection can improve outcomes.

How Do You Reconstitute LL-37?

LL-37 typically comes as a lyophilized (freeze-dried) powder. Reconstitute with bacteriostatic water — never saline or sterile water, as BAC water contains 0.9% benzyl alcohol that prevents bacterial growth and extends shelf life to 4-6 weeks.

Use our peptide dosing calculator to determine the exact amount of BAC water to add based on your vial size and desired dose per injection.

How Long Should a LL-37 Cycle Last?

Standard LL-37 cycles run acute use as needed. This timeframe is based on the compound's mechanism and the time needed to observe measurable effects.

Achieves 3+ log reduction of S. aureus biofilms within 5 minutes at therapeutic concentrations. A derivative (omiganan/ropocamptide) advanced to late-stage clinical trials for catheter-site infections. Multiple antimicrobial peptides in this class entering human trials.

What Side Effects Can Affect Dosing?

Dose-dependent cytotoxicity to human cells above 75 mcg/mL. Hemolytic effects at high concentrations. Proteolytic degradation limits bioavailability. Potential immune overstimulation.

If side effects emerge, the first step is typically reducing the dose rather than discontinuing entirely. Most LL-37-related side effects are dose-dependent.

How Does LL-37 Dosing Change When Stacking?

Pairs with BPC-157 for wound healing — LL-37 handles antimicrobial defense while BPC-157 promotes tissue repair.

When stacking, some researchers reduce individual peptide doses by 20-30% since synergistic effects mean full doses of each aren't always necessary.

What Is the Bottom Line on LL-37 Dosing?

Start at 100, dose topical or local application as needed, and run cycles of acute use as needed. Monitor your response and adjust within the established range.

Source matters — always use research-grade LL-37 from vendors with third-party COA testing. Underdosed or contaminated products are the most common reason for poor results.

Related Reading

• LL-37 Benefits
• LL-37 Side Effects
• LL-37 Stacking Guide
• LL-37 Cycle Guide
• LL-37 Research
• BPC-157 Complete Guide

Frequently Asked Questions