Below you’ll find a map of the available medical marijuana dispensaries in Detroit. Registered medical patients can purchase up to 2.5 ounces of cannabis. Michigan does not extend reciprocity to out-of-state cardholders. While recreational cannabis is permitted in Detroit, and adults 21 and over can possess up to 2.5 ounces, recreational dispensaries are not open yet. The nearest recreational dispensaries are located in Hamtramck and Hazel Park.