The Methamphetamine Precursor Control Act is an Illinois state law that was signed into law on November 16, 2005, and took effect on January 15, 2006. The MPCA is an act used to create significant barriers such as the requirement to present ID to purchase cold medication that contains pseudoephedrine which could be used to produce methamphetamine. This is one of many state laws regulating the supply of pseudoephedrine that preceded the federal Combat Methamphetamine Epidemic Act of 2005.