US and Mexican controls on precursor chemicals may reduce cocaine and meth use in the US

In December 2006, the USA regulated sodium permanganate, a chemical essential to the manufacture of cocaine. In March 2007, Mexico closed a chemical company accused of illicitly importing more than 60 tons of pseudoephedrine, a methamphetamine precursor chemical. A new study has found that those events were associated with large, extended reductions in cocaine and methamphetamine users in the USA.