LearnLiberty has a helpful video on this:
Stevan Duke and Albert Gross have an excellent discussion of the potency effect in America’s Longest War, and Edward M. Brecher has offered a very thorough history of prohibition’s effect on heroin use in Licit and Illicit Drugs. The latter is available on Amazon for just 50 cents at time of writing, the former just 14 cents. They are older books, but history hasn’t changed.
