How many units per mL does a BPC-157 syringe hold?

A standard U-100 insulin syringe always reads 100 units per mL, no matter how the vial was reconstituted. What changes with concentration is mcg per unit — how much BPC-157 is in each of those 100 units — not the units-per-mL scale itself.

How many units is a 250 mcg BPC-157 dose from a 5 mg vial in 2 mL of water?

That mix works out to 2500 mcg/mL, or 25 mcg per unit. A 250 mcg dose is 250 ÷ 25 = 10 units.

Does adding more bacteriostatic water change the units per mL?

No. Units per mL is fixed at 100 by the syringe itself. Adding more water lowers the concentration, which means more units are needed to draw the same dose. The total BPC-157 in the vial doesn't change.

How many total doses does a 5 mg BPC-157 vial provide?

At a 250 mcg dose, a 5 mg (5000 mcg) vial provides 20 doses, regardless of how much water was used to reconstitute it. Water volume changes the draw volume per dose, not the number of doses the vial contains.

BPC-157 Units Per mL Calculator

By PeptCalc Research — Medically reviewed by David Mansour, MD — Last reviewed July 15, 2026

BPC-157 vials are sold in milligrams, but the number that actually matters at the syringe is units per mL — and the honest answer is that this figure never changes. A U-100 insulin syringe is built to read 100 units per mL, full stop. What changes with your reconstitution choice is how much BPC-157 sits inside each of those units. This is a research reference for that math: how vial concentration sets mcg per unit, and how to turn a target dose into an exact draw. It is written for research purposes only and is not medical advice.

What "units per mL" actually means

Every U-100 insulin syringe divides 1 mL into 100 units. That ratio is printed on the barrel and doesn't move — it's a property of the syringe, not the peptide. Searching for a "units per mL calculator" usually isn't really asking about the syringe scale; it's asking a different question in disguise: given how I mixed this vial, how much BPC-157 is in each unit, and how many units does my target dose take?

What changes: mcg per unit

Concentration is vial mass divided by water volume. Once you know mcg/mL, dividing by 100 gives mcg per unit — the number that actually drives your draw.

For a 5 mg (5000 mcg) BPC-157 vial:

Water added	Concentration	mcg per unit	Units per mL
1 mL	5000 mcg/mL	50 mcg/unit	100
2 mL	2500 mcg/mL	25 mcg/unit	100
5 mL	1000 mcg/mL	10 mcg/unit	100

Units per mL never leaves 100. Mcg per unit drops as water volume rises, which is the entire lever you're pulling when you choose a reconstitution ratio.

Worked example

5 mg vial + 2 mL bacteriostatic water → 2500 mcg/mL

mcg per unit: 2500 ÷ 100 = 25 mcg/unit
250 mcg dose ÷ 25 mcg/unit = 10 units
500 mcg dose ÷ 25 mcg/unit = 20 units

10 mg vial + 2 mL bacteriostatic water → 5000 mcg/mL

mcg per unit: 5000 ÷ 100 = 50 mcg/unit
250 mcg dose ÷ 50 mcg/unit = 5 units
500 mcg dose ÷ 50 mcg/unit = 10 units

Same 250 mcg dose, same syringe, two different unit readings — 10 units versus 5 — because the vials were mixed at different concentrations. Enter your own vial size and water volume into the peptide calculator to skip this arithmetic, or use reverse mode to find the water volume that lands your usual dose on a round number.

Total doses per vial doesn't change

Water volume changes the units per dose. It does not change how much BPC-157 is in the vial or how many doses that vial holds. A 5 mg (5000 mcg) vial at a 250 mcg dose provides 20 doses whether it was reconstituted in 1 mL, 2 mL, or 5 mL — only the draw size per dose shifts:

Water added	Units for a 250 mcg dose	Doses in the vial
1 mL	5 units	20
2 mL	10 units	20
5 mL	25 units	20

Choosing a ratio for a clean reading

None of the rows above is wrong — 5000 mcg total BPC-157 splits into 20 doses either way. What differs is how easy the draw is to read and double-check. A dose that lands on 10 or 20 units is generally easier to draw accurately on a U-100 syringe than one that lands on 3 units or 78 units, simply because small errors matter proportionally more at the low end and the barrel is easier to read at round marks.

Reconstitution steps

Gather the BPC-157 vial, bacteriostatic water, alcohol swabs, and a U-100 insulin syringe.
Swab both vial stoppers with alcohol.
Draw the water volume your chosen ratio calls for.
Inject it slowly down the inside wall of the vial, not directly onto the powder.
Swirl gently until fully dissolved — don't shake.
Confirm the resulting concentration matches what you entered into the calculator before drawing a dose.

For the general steps that apply to any peptide vial, see how to reconstitute peptides.

Common mistakes

Treating "units per mL" as if it varies by peptide or concentration. It doesn't — it's fixed at 100 on a U-100 syringe. The number that actually varies is mcg per unit.
Reusing a mcg-per-unit figure across a different water volume. Change the water, and the mcg-per-unit figure has to be recalculated — it doesn't carry over from a previous mix.
Confusing a smaller unit count with a smaller dose. In the worked example above, 5 units and 10 units both deliver the same 250 mcg — the unit count only reflects the concentration used, not the amount of BPC-157 delivered.
Using a syringe that isn't U-100. Every calculation here assumes 100 units = 1 mL. A different syringe scale changes the unit conversion.

Use the calculator

Enter your BPC-157 vial size and water volume into the peptide calculator to get concentration, mcg per unit, and the exact syringe units for any target dose. Reverse mode runs it the other way — enter your dose and the units you want to land on, and it returns the water volume that gets you there.

For related math, see the BPC-157 dosage calculator and the TB-500 reconstitution ratio calculator. The calculator does the arithmetic; this guide explains what the units on the syringe actually represent.