It depends on the vial size and your desired injection volume. The more BAC water you add, the more dilute the solution and the larger volume you'll need to inject per dose. Common example: Vial | BAC Water | Concentration | 2.5 mg dose = --- | --- | --- | --- 30 mg | 3 mL | 10 mg/mL | 25 units 30 mg | 2 mL | 15 mg/mL | ~17 units 30 mg | 1.5 mL | 20 mg/mL | 12.5 units 60 mg | 3 mL | 20 mg/mL | 12.5 units Use an online peptide calculator to determine exact amounts. Less BAC water = more concentrated = smaller injections, which is preferred at higher doses.