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How-to · reconstitution

How to reconstitute LL-37 5 mg

In this example, 1 mL of bacteriostatic water in a 5 mg LL-37 vial gives 5.00 mg/mL. An example 200 mcg amount is then 4.0 units on a U-100 syringe.

This example lands on a syringe line. More water makes a weaker mix and a bigger draw. Less water makes a stronger mix and a smaller one. The amount of LL-37 stays the same. Use the diluent and volume specified for your product; the arithmetic alone does not choose them.

What matters first

Example water volume
1 mL
Resulting strength
5.00 mg/mL
Example 200 mcg dose
4.0 U-100 units

How much bacteriostatic water for a 5 mg LL-37 vial?

◆ Unique to the 5 mg vialU-100 example draws
Water addedConcentrationPer U-100 unitExample: 200 mcg =
1 mL5.00 mg/mL50 mcg4.0 units
2 mL2.50 mg/mL25 mcg8.0 units
3 mL1.67 mg/mL16.67 mcg12.0 units

Straight arithmetic: concentration = 5 mg ÷ liquid volume, and 1 U-100 unit = 0.01 mL. The example column shows the math at 200 mcg; it is not a dose recommendation.

The table compares possible concentrations; it does not establish which diluent or volume suits your product. Follow its dispensing instructions.

“Hard to measure” means the example draw is below two U-100 units. “Won’t fit” means it exceeds this syringe’s capacity.

LL-37 5 mg vial: example mixing volumes. Each row is what that amount draws on a U-100 syringe. 1 mL makes 5.00 mg/mL, or 50 mcg a unit, and 200 mcg is 4 units. 2 mL makes 2.50 mg/mL, or 25 mcg a unit, and 200 mcg is 8 units. 3 mL makes 1.67 mg/mL, or 16.67 mcg a unit, and 200 mcg is 12 units. The barrel drawn here is filled to 4 units, the draw at 1 mL. The sum is 5 mg divided by the liquid volume. One U-100 unit is 0.01 mL.
The 5 mg vial at 1 mL on a U-100 barrel. 200 mcg fills to 4.0 units, at 5.00 mg/mL.

Medically reviewed by Kenneth Montecillo, MD2026-09-07open the primary sources

What is LL-37?

LL-37 is a peptide 37 amino acids long that your own white blood cells make. It kills bacteria by breaking open their outer membrane.

How many units is a documented dose from this vial?

The table above uses one worked example. These are the published quantities, converted into marks on a U-100 barrel at each listed liquid volume for a 5 mg vial. Where a quantity was never studied by injection, the row says so.

250–500 mcg — studied in a trial

250–500 mcg once every 7 days for up to 8 weeks, injected into a cutaneous or subcutaneous melanoma deposit, under the skin. (2 participants at 250 mcg, 1 at 500 mcg — 3 treated in all).

Water addedConcentrationDraw, low to high
1 mL5.00 mg/mL5.0 to 10.0 units
2 mL2.50 mg/mL10.0 to 20.0 units
3 mL1.67 mg/mL15.0 to 30.0 units

Human trialInduction of Antitumor Response in Melanoma Patients Using the Antimicrobial Peptide LL37 (NCT02225366) — MD Anderson Cancer Center, phase 1/2, completed, results posted · retrieved 2026-08-12

Three volumes, three clean readings, three people in the evidence

Every documented water option produces a whole-number syringe reading. All three displayed volumes fit the illustrated scale. The injection study cited here treated three people; separate topical research addresses a different preparation and use.

3Read the full vial record — 3 notes

Every row lands on a graduation

Three listed volumes, three whole numbers of units. The spread is wide enough that the smallest reading is single figures and the largest is not.

The largest volume gives the longest reading at the same drug amount. That does not establish that extra diluent is appropriate, harmless or supported by instructions for a particular preparation.

The cited study used injections into tumors

The cited trial injected LL-37 into melanoma tumors in three people at two dose levels. The worked amount here differs from the trial’s starting amount per tumor. Neither the route nor the study dose transfers to this example.

Injecting into a tumor puts a peptide somewhere entirely unlike fat, and three people is not a group anyone can generalize an amount from.

Topical and tumor-injection findings answer different questions

In the larger trial, on leg ulcers, the two lower strengths improved healing and the highest did not differ from placebo.

The topical results do not form a combined dose-response curve with tumor injections. They involve a different application, condition and endpoint. Twenty-five worked portions cannot be read as a regimen supported by either study.

How do you mix it, step by step?

  1. Wipe both stoppers with an alcohol swab and let them dry.
  2. Check the product’s mixing instructions for the correct diluent and volume before drawing it up.
  3. Let the water run slowly down the inside wall of the LL-37 vial, rather than jetting it onto the powder.
  4. Follow the product’s instructions for mixing and checking the solution before use. Do not assume every powder uses the same method.
  5. Store it as the dispensing label directs. What happens after mixing differs by product — some labels direct against refrigerating the mixed solution at all.

What if your water volume is not on the table?

The calculator lets you enter your product’s vial strength and mixing volume, then shows the arithmetic for your syringe.

Open the LL-37 calculator →

Where to read next about LL-37

The arithmetic on this page is only half the question. These are the pages that carry the other half.

How strong the evidence is for LL-37

The strongest source for LL-37 is a foreign approval or thin human data.

The generic calculator behind the LL-37 one

Vial strength and water volume in and the exact mark out, with LL-37 as context

Find mixing guides for LL-37

Find vial-specific mixing tables as you explore LL-37.

Where LL-37 stands with the regulator, and when

Approval status, proceedings and the date attached to each, with LL-37 as one example

1primary source, each with the day we read it — open the documents used on this page