How do I adjust my dosing calculations if I accidentally added too much bacteriostatic water?

Recalculate concentration using actual volume added. For example, a 5mg vial with 2.5mL instead of 2mL yields 2mg/mL instead of 2.5mg/mL. To achieve your target 500mcg dose, draw 0.25mL instead of 0.2mL (500mcg ÷ 2mg/mL = 0.25mL). Always verify calculations before injection. USP pharmaceutical calculations provide error correction methods.