LL-37 dosage chart: how many units on the syringe

How the conversion works

A U-100 insulin syringe is marked in insulin units, not in milligrams or milliliters. The scale is fixed: 100 units is 1 mL of liquid, so 1 unit is one hundredth of a milliliter. The syringe has no idea what is inside it. It only measures volume.

That means the number of units for a given milligram dose depends entirely on how concentrated the vial is. Concentration is the vial's peptide mass divided by the water you added. A 10 mg vial with 1 mL of bacteriostatic water gives 10 mg/mL. The same vial with 2 mL gives 5 mg/mL, and with 3 mL it gives 3.33 mg/mL.

To get units, divide your dose in milligrams by the concentration to get milliliters, then multiply by 100. The table on this page has already done that for every combination of the vial sizes and water volumes seen in listings, so you do not need to run the arithmetic yourself. You do need to know which water volume you actually used.

What the table shows

The first thing to notice is that the peptide mass in the vial never changes when you add more water. Adding 3 mL instead of 1 mL does not create more LL-37. It spreads the same amount over a larger volume, so each unit on the syringe carries less peptide and the same dose takes more units to draw.

The second thing is how small the numbers get at low volume. From a 10 mg vial in 1 mL, a 0.1 mg dose lands at 1 unit. That is a single tick mark on a U-100 syringe. Reading a single tick accurately, and pushing exactly that much out, is harder than reading a mark further up the barrel. The 3 mL rows put the same doses higher on the scale, which is the practical reason people choose larger water volumes for small doses.

Third, the relationships are strictly linear. Double the dose at a fixed concentration and the units double. Triple the water at a fixed dose and the units triple. Nothing in this arithmetic is approximate except the rounding to the nearest whole unit, and the 0.25 mg row at 3 mL is the one where that rounding is most visible.

Vial size changes everything

The listings for LL-37 include both 5 mg and 10 mg vials. The computed table on this page is for the 10 mg vial. A 5 mg vial reconstituted with the same water volume is half as concentrated, so every dose drawn from it needs twice the units.

This is the single most common source of error with peptide arithmetic. Two vials can look identical, sit in the same box, and carry labels that differ only in one digit. The syringe reading that was correct for one is wrong for the other by a factor of two. Check the label, not your memory of the last vial.

The same applies to water. If you intended 2 mL and drew 3 mL, every subsequent unit reading is off. Write the water volume on the vial after you reconstitute it. That single note removes the most likely reason a later dose is miscalculated.

What this page does not tell you

LL-37 is not approved by any regulator for human use. This page is arithmetic only. It converts milligrams to syringe units and does nothing else.

We hold no reliable human pharmacokinetic data for LL-37. That means this site makes no claim about how long it stays in the body, how quickly it clears, or whether it builds up with repeated administration. Any page that gives you a schedule for this compound is not drawing on data we can verify.

The dose amounts in the table are the figures that appear in vendor listings. Listing a number is not evidence that the number is appropriate, effective or safe. This site has no medical review process and cannot tell you what dose to use, what to expect from it, what adverse effects occur, or whether using it is a reasonable thing to do. Those are clinical questions and they need a clinician, not a conversion table.

What we do not know

We hold no reliable human pharmacokinetic data for LL-37, so this site makes no claims about its half life, how long it takes to clear, or how it accumulates. The arithmetic below concerns concentration and volume only.

This page answers arithmetic and handling questions. It does not tell you what dose to take, what to expect, or whether anything is appropriate for you, and there is no medical review behind it.

Common questions

How many units is 0.5 mg of LL-37?

It depends on the concentration. From a 10 mg vial in 1 mL, 0.5 mg is 5 units on a U-100 syringe. The same vial in 2 mL makes it 10 units, and in 3 mL it is 15 units. The dose in milligrams is identical in all three cases.

Does adding more bacteriostatic water reduce the dose?

No. The vial contains a fixed mass of peptide regardless of how much water you add. More water lowers the concentration, so the same milligram dose occupies more volume and reads as more units on the syringe. The dose only changes if you draw a different number of units.

Is 1 unit too small to measure accurately?

One unit is the smallest graduation on a standard U-100 syringe, so there is no margin for reading between marks. Using more bacteriostatic water moves the same dose further up the barrel, where marks are easier to line up. We cannot tell you which volume to choose, only that the arithmetic scales in a fixed way.

Can I use this table for a 5 mg vial?

No. The table is computed for a 10 mg vial. A 5 mg vial with the same water volume is half as concentrated, so every reading doubles. Confirm the milligram figure on the label before you use any conversion.

How often should LL-37 be dosed?

This site does not answer that. We hold no reliable human pharmacokinetic data for LL-37, so we make no claims about its half life, clearance or accumulation, and therefore none about frequency or timing. The arithmetic here covers concentration and volume only.

Why does the 0.25 mg dose at 3 mL round oddly?

The concentration at 3 mL is 3.33 mg/mL, which does not divide into 0.25 mg to give a whole number of units. The table reports the nearest whole unit, because that is what a U-100 syringe can actually be set to. The rounding is more noticeable at smaller doses.