What syringe units mean

On a U-100 insulin syringe, one "unit" = 0.01 mL. So 10 units = 0.1 mL, 25 units = 0.25 mL, and so on. When our planner tells you to draw "10 units", it means to pull the plunger back until the top of the plunger sits at the 10-unit mark.