Calculating Number of MG's of Iodine per Drop of Lugol's Solution: LUGOL'S 5%: Each VERTICAL drop is about 6.25 mg of iodine. (The correct way to make a drop is to hold the dropper vertical and squeeze the rubber topper) HORIZONTAL drops - when the dropper is held side to side there is twice as much iodine per drop. Approximately 12.5 mg LUGOL'S 2%: Approximately 1/2 half the above measurements