Lugols solution contains 5% iodine and 10% potassium iodide in pure water. It may be used as a iodine supplement or to purify drinking water. For more information refer to the article titled "iodine" in the articles section of this website. NB: Lugol's acually does not come in a droppr bottle as the image indicates. Due to its corrosive nature it tends to erode the rubber dropper causing it to leak. Limits apply to the quantity supplied!