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How much bacteriostatic water should I add?

There is no single right volume. Water changes concentration, not the total amount in the vial. More water means a larger, easier-to-read draw for the same amount. Use reverse mode to pick the water volume that lands your amount on a chosen unit mark.

Math only, not medical advice. This page converts numbers; it does not recommend any compound or amount.

Draw to
10 units
= 0.1 mL · concentration 2.5 mg/mL (2500 mcg/mL) · 20 draws per vial
Concentration = 5 mg ÷ 2 mL = 2.5 mg/mL
Volume = 250 mcg ÷ 2500 mcg/mL = 0.1 mL
Units = 0.1 mL × 100 (U-100) = 10 units
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Math only, not medical advice. Verify every number yourself.

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