LL-37 Calculator

LL-37 dosage calculator

The LL-37 dosage calculator above converts a target dose into exact syringe units based on your vial size and how much bacteriostatic water you used to reconstitute it. LL-37 is commonly sold in 5 mg, 10 mg vials. The calculator supports both U-100 and U-40 insulin syringes and flags draws that are too large for the syringe barrel or too small to measure accurately. A human cathelicidin antimicrobial peptide derived from hCAP-18, studied for innate immune and antimicrobial mechanisms. Enter your target dose in the calculator above to see the exact number of units to draw.

LL-37 dosage chart

LL-37 and Antimicrobial peptides

LL-37 is a Human cathelicidin antimicrobial peptide. A human cathelicidin antimicrobial peptide derived from hCAP-18, studied for innate immune and antimicrobial mechanisms.

LL-37 is a 37-amino-acid cationic antimicrobial peptide derived from the C-terminal portion of human cathelicidin (hCAP-18). Published research has studied LL-37 in contexts of innate immunity, antimicrobial activity against bacteria and viruses, and wound healing. It is the only cathelicidin-family antimicrobial peptide identified in humans and has been the subject of extensive basic research on host defense. LL-37 is not approved by the FDA for human use. Research-grade LL-37 sold by chemical supply companies is labeled for laboratory research purposes only.

See all Antimicrobial peptides →

How to reconstitute LL-37

Research vendors typically offer LL-37 in 5 mg or 10 mg lyophilized vials. Reconstitution with 2–3 mL of bacteriostatic water is commonly reported.

Reconstituting LL-37 is the same unit-conversion process used for any lyophilized peptide:

1. Draw your chosen volume of bacteriostatic water into a syringe.
2. Inject the bacteriostatic water slowly down the side of the LL-37 vial — do not shoot it directly onto the powder.
3. Swirl gently until the powder fully dissolves. Do not shake.
4. Store the reconstituted vial refrigerated.
5. To dose, calculate your draw volume: divide your target dose by the concentration (vial mg ÷ water mL = mg/mL). The calculator above does this automatically.

For LL-37 specifically, 5 mg, 10 mg vials are common. A typical reconstitution adds 2 mL of bacteriostatic water, producing a concentration of 5 mg/mL for the 10 mg vial size.

LL-37 half-life and storage

Published pharmacokinetic data on systemic LL-37 is limited. Available research suggests a plasma half-life on the order of hours.

Lyophilized LL-37 is typically stored frozen for long-term storage or refrigerated for short-term use. Reconstituted solutions are commonly kept refrigerated and protected from light.

Common LL-37 dosing mistakes

Most LL-37 draw errors are unit errors, not arithmetic errors: confusing mg with mcg (1 mg = 1,000 mcg), or reading a U-40 syringe with U-100 math — the same printed mark holds 2.5× the volume. Two more worth avoiding: leaving the vial unlabeled, so the concentration and reconstitution date are lost, and under-diluting to the point where the draw is under about one unit and can no longer be read accurately.

Each of these is covered in full in the guides: reconstitution math from first principles, U-100 vs U-40 syringes, storage and shelf life, and how to reconstitute peptides.