Since 1996, 20 states and Washington, DC have passed laws allowing smoked marijuana to be used for a variety of medical conditions. It is important to recognize that these state marijuana laws do not change the fact that using marijuana continues to be an offense under Federal law. Nor do these state laws change the criteria or process for FDA approval of safe and effective medications.
Many of these state medical marijuana laws originated in order to create a legal defense to state criminal possession laws or to remove state criminal penalties for purported medical use of marijuana. Since then, many have evolved into state authorization for state-based production and distribution of marijuana for purported medical purposes. These state laws vary greatly in their criteria and implementation, and many states are experiencing vigorous internal debates about the safety, efficacy, and legality of their marijuana laws. Many local governments are even creating zoning and enforcement ordinances that prevent marijuana dispensaries from operating in their communities.
States with medical marijuana laws often have some form of patient registry, which may provide some protection against state arrest for possession up to a certain amount of marijuana for personal medical use. Medical marijuana growers or dispensaries are authorized in some of these states and may be limited to a certain number of plants or products per medical user. Regulation of marijuana for purported medical use may also exist at the county and city level, in addition to state laws.