re: the difference

each drop contains the same amount of total Iodine as lugols, 6.25mg. whereas Lugols breaks down to 3.75mg of Iodine in the form of Iodide and 2.5mg of elemental iodine, WIS consists of 5.25mg of Iodine in the form of Iodide and 1mg of elemental iodine.

if your serving is one drop per day, you will obtain 6.25mg of total iodine per serving and there will be 300 servings total. the entire one half ounce contains 1875mg of total iodine content.