States have long enacted drug laws that depart from federal laws and regulations.  In the early twentieth century, several states prohibited marijuana while it remained federally unregulated.  In the 1960s, states started criminalizing psychedelic substances.  Shortly thereafter, in the early 1970s, they started reversing the trend to criminalize drugs by reducing or eliminating criminal penalties associated with personal marijuana use.  State-level decriminalization accelerated in the 1990s and 2000s.

More recently, states have extended drug policy reforms to other substances, including psychedelics, stimulants, and opioids.  Some states have eliminated criminal penalties while others have replaced criminal penalties with fines or diversion to drug treatment programs and other support services.  Some have funded clinical trials or policy research.  Others have legalized facilities where people can consume federally controlled substances socially or with support from medical professionals.  Meanwhile, many states have shifted away from decriminalizing federally illegal drugs to regulating their manufacture, testing, distribution, and sale.

This Essay provides a typology of state drug laws comprising thirteen categories, including decriminalization, recriminalization, adult use, supported adult use, medical use, supported medical use, religious use, social consumption, safe consumption, clinical research, policy analysis, trigger laws, and food and agricultural laws.  Several states have enacted hybrid legislation that blends features from different categories.  A higher‑level categorization can also be imposed onto the typology, dividing the categories into three broader groups, including laws regarding independent drug use, supervised drug use, and drug policy or procedure.