P-21 10mg Reconstitution: How Much Bacteriostatic Water & How Many Units

A 10mg vial of P-21 contains 10,000 mcg. After you add bacteriostatic water, the amount of water decides the concentration — and therefore how many units you draw on a U-100 insulin syringe (1 ml = 100 units). The tables below cover the common water amounts.

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Concentration by water amount

Water added	Concentration	Per 1 unit (0.01 ml)	Per 10 units (0.1 ml)
1 ml	10 mg/ml	100 mcg	1 mg
2 ml	5 mg/ml	50 mcg	500 mcg
3 ml	3.33 mg/ml	33.33 mcg	333.33 mcg

How many units to draw

Example doses across the research range listed for P-21 (100 mcg–300 mcg). Units are on a U-100 insulin syringe.

Dose	With 1 ml	With 2 ml	With 3 ml	Doses per vial
100 mcg	1 units	2 units	3 units	100
150 mcg	1.5 units	3 units	4.5 units	66
250 mcg	2.5 units	5 units	7.5 units	40
300 mcg	3 units	6 units	9 units	33

How to mix it

Wipe the vial stoppers with alcohol and let them dry.
Draw your chosen amount of bacteriostatic water into a sterile syringe.
Inject the water slowly down the inside wall of the P-21 vial — not directly onto the powder.
Swirl gently until clear. Do not shake.
Label the vial with the date and concentration, and store it in the refrigerator.

Full walkthrough: Peptide Reconstitution Guide · Injection Guide · P-21 research profile

FAQ

How much bacteriostatic water do I add to a 10mg P-21 vial?

Common choices are 1 ml, 2 ml, 3 ml. With 2 ml the concentration is 5 mg/ml. More water makes each dose a larger, easier-to-measure draw; less water keeps injection volume small. The amount of water does not change the dose — only how many units you draw.

How many units is 100 mcg of P-21 from a 10mg vial?

With 2 ml of bacteriostatic water, 100 mcg is 2 units on a U-100 (1 ml) insulin syringe. See the table above for other water amounts.

How many doses are in a 10mg P-21 vial?

At 100 mcg per dose, a 10mg vial holds about 100 doses. At higher doses it holds fewer — see the table.