Sold as a 4 ounce dark dropper bottle of Methylene Blue + a 1 ounce dropper bottle of Ascorbic Acid.   They can be taken together if desired, or the ascorbic acid is helpful for cleaning up any small drips of Methylene Blue (it's also a beautiful blue dye!).    Dosage can be anywhere from a few drops in water or other beverage or much higher.