How do I calculate peptide reconstitution?

Divide the vial size in milligrams by the volume of bacteriostatic water you add to get the concentration in mg/ml. On a U-100 insulin syringe, 1 unit equals 0.01 ml, so multiply the concentration by 10 to get micrograms per unit, then divide your desired dose by that number to get the units to draw.

How much BAC water should I add to a peptide vial?

There is no single correct amount; the water volume only changes the concentration, not the total peptide. Common choices are 1-3 ml per vial. Use less water for a stronger concentration (fewer syringe units per dose) or more water for easier measurement of very small doses.

How many units is my dose on an insulin syringe?

Units to draw = desired dose in mcg ÷ (vial mg × 1000 ÷ water ml ÷ 100). For example, a 5 mg vial reconstituted with 2 ml of BAC water gives 25 mcg per unit, so a 250 mcg dose is 10 units.

How many doses are in one vial?

Divide the total vial content in micrograms by your per-dose amount. A 5 mg (5000 mcg) vial at 250 mcg per dose yields 20 doses, regardless of how much water you add.

Tools

Reconstitution calculator.

Enter your vial size, bacteriostatic water volume, and target dose. Get exact insulin-syringe units, concentration, and doses per vial.

Peptide (optional)

Vial size (mg)

BAC water (ml)

Desired dose (mcg)

Results

Draw on a U-100 insulin syringe

10 units

= 0.1 ml per dose

Concentration

2.5 mg/ml

25 mcg per unit

Doses per vial

at 250 mcg each

Educational reference only, not medical advice. Verify every calculation yourself and consult a licensed clinician before use.

How the math works

Reconstitution is just dilution: the milligrams in your vial never change, only how much liquid they are dissolved in. Concentration equals vial size divided by water volume. A 5 mg vial with 2 ml of bacteriostatic water gives 2.5 mg/ml.

Insulin syringes make small-volume dosing practical. On a U-100 syringe, 100 units equal 1 ml, so each unit is 0.01 ml. At 2.5 mg/ml, one unit contains 25 mcg, and a 250 mcg dose is exactly 10 units.

Every peptide profile on this site lists typical vial sizes and dosage ranges. Browse the full peptide index or check the glossary for terms like BAC water and subcutaneous injection.

Common questions

How do I calculate peptide reconstitution?: Divide the vial size in milligrams by the volume of bacteriostatic water you add to get the concentration in mg/ml. On a U-100 insulin syringe, 1 unit equals 0.01 ml, so multiply the concentration by 10 to get micrograms per unit, then divide your desired dose by that number to get the units to draw.
How much BAC water should I add to a peptide vial?: There is no single correct amount; the water volume only changes the concentration, not the total peptide. Common choices are 1-3 ml per vial. Use less water for a stronger concentration (fewer syringe units per dose) or more water for easier measurement of very small doses.
How many units is my dose on an insulin syringe?: Units to draw = desired dose in mcg ÷ (vial mg × 1000 ÷ water ml ÷ 100). For example, a 5 mg vial reconstituted with 2 ml of BAC water gives 25 mcg per unit, so a 250 mcg dose is 10 units.
How many doses are in one vial?: Divide the total vial content in micrograms by your per-dose amount. A 5 mg (5000 mcg) vial at 250 mcg per dose yields 20 doses, regardless of how much water you add.