States that have legalized the sale and use of cannabis have generally exhibited similar patterns in cannabis sales over time. States start by legalizing medical cannabis. As medical cannabis programs are rolled out, numbers of cannabis patients and sales of medical cannabis products increase over time. After medical cannabis has been legalized for some years, many states eventually also legalize cannabis for recreational (adult use) purposes. If and when a state legalizes recreational cannabis, total cannabis sales continue to rise, where sales for recreational uses increase, but sales for medical uses decrease (see Figure 1).