The most common ingredient in meth is pseudoephedrine or ephedrine, commonly found in cold medicine. Through a cooking process the pseudoephedrine or ephedrine is chemically changed into meth. The ingredients that are used in the process of making meth can include: ether, paint thinner, Freon®, acetone, anhydrous ammonia, iodine crystals, red phosphorus, drain cleaner, battery acid, and lithium (taken from inside batteries). (in fallout only)