LL-37 reconstitution calculator.
A 2 mg vial of LL-37 dissolved in 2 mL of bacteriostatic water is 1,000 mcg per mL, which is 10 mcg per unit on a U-100 insulin syringe.
LL-37 is the body's own antimicrobial peptide, and its human trials applied it topically to chronic leg ulcers, so the only human figures for it are concentrations rather than amounts per injection. Vials are 2 mg and 5 mg, and because the peptide is strongly cationic it is dissolved in dilute acid before it is made up to volume.
Reference range often cited for LL-37: 100–200 mcg, shown for orientation only, not a recommendation. Enter your own target below. Read the evidence →
Each unit on a 100u · 1.0 mL syringe ≈ 10 mcg of this solution.
Show the math
More water → lower concentration → more units for the same amount.
How much bacteriostatic water for a LL-37 vial?
There is no single correct volume. More water gives a weaker solution, so each unit on the syringe holds less LL-37 and a given amount takes more units to measure, which is easier to read on the syringe scale. Less water does the opposite. These tables show the concentration for each common vial size across the usual volumes. They are arithmetic, not a recommendation of how much to take.
| BAC water | Concentration | Per 1 unit | Per 10 units |
|---|---|---|---|
| 1 mL | 2,000 mcg/mL | 20 mcg | 200 mcg |
| 1.5 mL | 1,333 mcg/mL | 13.3 mcg | 133 mcg |
| 2 mL | 1,000 mcg/mL | 10 mcg | 100 mcg |
| 2.5 mL | 800 mcg/mL | 8 mcg | 80 mcg |
| 3 mL | 667 mcg/mL | 6.7 mcg | 67 mcg |
| BAC water | Concentration | Per 1 unit | Per 10 units |
|---|---|---|---|
| 1 mL | 5,000 mcg/mL | 50 mcg | 500 mcg |
| 1.5 mL | 3,333 mcg/mL | 33.3 mcg | 333 mcg |
| 2 mL | 2,500 mcg/mL | 25 mcg | 250 mcg |
| 2.5 mL | 2,000 mcg/mL | 20 mcg | 200 mcg |
| 3 mL | 1,667 mcg/mL | 16.7 mcg | 167 mcg |
How many units of LL-37 is a given amount?
Divide the amount in micrograms by the micrograms per unit for your mix. With a solution of 2,500 mcg per mL, one unit on a U-100 syringe holds 25 mcg, so any amount in mcg divided by 25 gives the units. The calculator above does this for you from your own vial and water, and the tables give the per-unit figure for each common mix.
Why does LL-37 need its own calculation?
- 5 mg made up to 2 mL is 2,500 mcg/mL, which the calculator also shows as 2.5 mg/mL, the form a topical concentration is written in. A 2 mg vial in the same volume is 1 mg/mL.
- The documented approach adds a small volume of dilute acetic acid first, swirls until fully clear, then brings it to the final volume with bacteriostatic water. The concentration is the vial mass over that total, acid included.
- A cloudy solution means some peptide is not in solution, and the calculated concentration then overstates what is actually in the liquid.
How is LL-37 administered, and what does the math look like?
How LL-37 is actually administered, with the concentration arithmetic written out. Amounts in these tables are illustrative examples of the math, never a recommendation.
LL-37: research formats
Choose the format you are researching to see route-specific notes.
Cationic antimicrobial peptide; requires acetic acid reconstitution.
LL-37 is a highly cationic peptide with a pI that causes aggregation in BAC water. Reconstitution follows the standard acid-first protocol: dissolve in 0.01–0.6% acetic acid, then dilute with BAC water. Commonly sold as 2 mg or 5 mg vials.
LL-37 reconstitution: add 0.2 mL of 0.6% acetic acid first, swirl until fully clear, then add BAC water to total 2.0 mL. Do not add all BAC water directly, or precipitation occurs.
LL-37 reconstitution: common questions
Why does LL-37 need acetic acid?
It is highly cationic and tends to aggregate when bacteriostatic water is added directly. Dissolving it in a small volume of dilute acetic acid first, then making it up to volume, is the documented approach, and the total volume is what sets the concentration.
How many units is 100 mcg of LL-37?
On 5 mg made up to 2 mL (2,500 mcg/mL) it is 4 units. On a 2 mg vial made up to 2 mL (1,000 mcg/mL) it is 10 units.
Is LL-37 approved for anything?
No. It is an endogenous human peptide studied as an investigational agent, with early-phase topical wound trials and no product holding marketing approval. The profile covers what those trials did and did not show.
What the evidence on LL-37 actually shows
Knowing the concentration is not the same as knowing whether to use it. These are the strongest studies behind the LL-37 profile, labelled with the study type PubMed itself assigns.
- Randomized controlled trial · 2021Evaluation of LL-37 in healing of hard-to-heal venous leg ulcers: A multicentric prospective randomized placebo-controlled clinical trialWound repair and regeneration : official publication of the Wound Healing Society [and] the European Tissue Repair Society · PMID 34687253
- Randomized controlled trial · 2014Treatment with LL-37 is safe and effective in enhancing healing of hard-to-heal venous leg ulcers: a randomized, placebo-controlled clinical trialWound repair and regeneration : official publication of the Wound Healing Society [and] the European Tissue Repair Society · PMID 25041740
- Review · 2016LL-37: Cathelicidin-related antimicrobial peptide with pleiotropic activityPharmacological reports : PR · PMID 27117377
This page is arithmetic on numbers you enter. It does not recommend an amount of LL-37, and nothing here is medical advice. For what the published evidence actually supports, read the LL-37 profile, and for regulatory status see is LL-37 legal. Reviewed June 1, 2026.
Different question? The general reconstitution calculator covers every compound on the site, the blend calculator handles multi-peptide stacks, and vial longevity turns a vial into weeks of supply.
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