Iodine used in J.Crow's Lugol's solution is derived from mined crystals, not from shellfishApproximately 1200 vertical drops per 2 oz. containerTo use as a water purifier add 3-6 drops per liter of waterAlways fresh does not expire Equivalent to USP or Higher 2 oz Dropper Bottle Calculating Number of MG's of Iodine and Iodide per Drop of LUGOL'S 2%: Each VERTICAL "metric" drop (= 1/20 ml) is approximately 1.0 mg of iodine and 2.0 mg of potassium iodide. The Iodide portion of Potassium Iodide is about 75% so that is 1.5 mg. Therefore the total Iodine plus Iodide is 1.0 + 1.5 = 2.5 mg and 2 drops is about 5.0 mg's of iodine/iodide (2.0 mg iodine, 3.0 mg iodide). Compared to iodine and potassium iodide tablets, J.CROW'S Lugol's Solution offers big savings. Approximately 1200 vertical drops per 2 oz. container. To use as a water purifier add 3-6 drops per liter of water. Trusted Original Since 1829 Low Heavy Metal Verified