Methamphetamine is a man-made stimulant that's been around for a long time. During World War II, soldiers were given meth to keep them awake. People have also taken the drug to lose weight and ease depression. Today, the only legal meth product is a tablet for treating obesity and attention deficit hyperactivity disorder. It's rarely used and is available only by prescription. Crystal meth is made with the ingredient pseudoephedrine, which is found in many cold medicines. It helps ease congestion. Because it's used to make meth, the federal government closely regulates products with this ingredient. Most of the crystal meth used in this country comes from Mexican “superlabs.” But there are many small labs in the U. S. Some are right in people's homes.