LL-37 (CAP-18) Reconstitution Calculator
Enter the amount you want to measure. The vial buttons will highlight which vial strengths create cleaner syringe-unit measurements.
What amount do you need?
Type the target amount, then choose mg or mcg. Example: 2mg or 500mcg.
Work the dose out from body weight
Syringe size:
Possible vial strengths:
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Example LL-37 (CAP-18) Titration Schedule
| Item | Details |
|---|---|
| Standard dose | 100–250 mcg once daily |
| Cycle | 2–4 week blocks / 2–4 off |
| Ceiling | ~500 mcg (bell-shaped) |
Response is bell-shaped: in the human topical trials the LOWEST concentration performed best and higher doses added local reactions. Injectable use has no published human data; human trials of the peptide (ropocamptide) are topical wound-healing only.
Possible vial strengths:
What Is It?
LL-37 (CAP-18)
Cathelicidin antimicrobial peptide.
Bacteriostatic Water
Sterile water containing a bacteriostatic preservative, commonly used when preparing multi-use research vials.
How To Mix LL-37 (CAP-18)
1
CleanUse alcohol swabs to clean the tops of both vials.
2
Draw BAC WaterDraw the selected amount of bacteriostatic water.
3
Inject SlowlyAdd the liquid slowly down the side of the vial.
4
Swirl GentlyDo not shake. Swirl gently until dissolved.
5
Store ProperlyStore as directed and protect from heat and light.
Best Practices & Common Mistakes
Best Practices
- Use sterile technique.
- Protect from light and heat.
- Store refrigerated when appropriate.
- Use clean syringe-unit math before measuring.
Common Mistakes
- Confusing milligrams with milliliters.
- Choosing an option with awkward decimal units.
- Using too little liquid for very small measurements.
- Shaking the vial aggressively.
LL-37 (CAP-18) Storage & Handling
Lyophilized Powder: −20°C (−4°F) for long-term storage (up to 24 months). Refrigeration 2–8°C (36–46°F) for short-term use (up to ~3 months). Original sealed vial in the freezer is safest.
Reconstituted Solution: 2–8°C (36–46°F), use within ~7–14 days. Keep sealed, avoid light, and do not repeat freeze-thaw cycles.
Reconstituted Solution: 2–8°C (36–46°F), use within ~7–14 days. Keep sealed, avoid light, and do not repeat freeze-thaw cycles.
Frequently Asked Questions
LL-37 is the only human cathelicidin — a 37-amino-acid antimicrobial peptide your immune cells make as a first-line defense, cut from a precursor protein called hCAP-18. Unlike the muscle or healing peptides, it's an innate-immunity molecule studied for killing bacteria, fungi, and viruses and breaking up biofilms.
In research and anecdotal protocols it's referenced in micrograms — often somewhere around 100 mcg per day subcutaneously, in short courses. These are reference figures, not an approved regimen, and the right dose is a clinical decision.
Add bacteriostatic water and swirl gently — don't shake. A 5 mg vial + 2.5 mL gives 2 mg/mL (2,000 mcg/mL), so a 100 mcg dose = 0.05 mL = 5 units on a U-100 syringe. Use the calculator above for your exact vial size.
LL-37 is genuinely broad-acting against bacteria, fungi like Candida, and some viruses, largely by punching holes in microbial membranes. But it has a real double edge: it's both anti- and pro-inflammatory, and too much of it is implicated in rosacea, where excess LL-37 drives the redness and visible vessels. So the same molecule that defends can also inflame, depending on context and amount.
Despite its "natural antibiotic" reputation, LL-37 is cytotoxic to human cells at higher concentrations and can tip from calming to inflammatory, which is one reason its clinical use has been hard to develop. It is not FDA-approved and remains an investigational research compound. Store the dry vial refrigerated and out of light; once mixed, keep cold and use within a few weeks.
Practical takeaway: If your goal involves weight management, metabolic health, recovery, physical performance, cognitive function, appearance, or general well-being, discuss it with a licensed healthcare professional. They can help you evaluate approved, evidence-based options rather than relying on an unapproved or investigational compound. This calculator is intended only for transparent research-reference calculations and does not determine an appropriate amount, recommend use, or replace professional medical guidance.
Important: This tool is for informational and research-reference purposes only. Not intended for human or veterinary use.