Sol Dept. makes this magnesium in a facility in the United States, and the formula is a single ingredient, magnesium bittern, with no capsules, binders, fillers or flavors. The magnesium chloride is already dissolved, so one dropperful in a glass of water or tea gives 110 milligrams, and a four-ounce bottle holds about 120 servings. A third party tests it for purity.