From the New York Times

DES MOINES, Jan. 18 - In the seven months since Iowa passed a law restricting the sale of cold medicines used to make methamphetamine, seizures of homemade methamphetamine laboratories have dropped to just 20 a month from 120. People once terrified about the neighbor’s house blowing up now walk up to the state’s drug policy director, Marvin Van Haaften, at his local Wal-Mart to thank him for making them safer.

But Mr. Van Haaften, like officials in other states with similar restrictions, is now worried about a new problem: the drop in home-cooked methamphetamine has been met by a new flood of crystal methamphetamine coming largely from Mexico.

Sometimes called ice, crystal methamphetamine is far purer, and therefore even more highly addictive, than powdered home-cooked methamphetamine, a change that health officials say has led to greater risk of overdose. And because crystal methamphetamine costs more, the police say thefts are increasing, as people who once cooked at home now have to buy it.