Since passage of California’s compassionate care act of 1996, intended to allow terminally ill patients to use marijuana for its purported ability to prevent wasting and reduce nausea, many states have passed similar legislation allowing physicians to recommend medical marijuana for a large number of conditions despite having no evidence to support such recommendations.

Earlier this week a large scoping review of marijuana as a treatment for a wide variety of medical conditions was published in the Journal of Systematic Reviews. The review included evidence from 72 systematic reviews (of hundreds of studies) and confirmed that there was no clinical evidence to support marijuana and marijuana-based products as effective treatment for any medical condition outside of very specific types of neuropathic pain. In fact, adverse effects were commonly reported, many serious. According to the authors of the review, the combined empirical data from hundreds of studies indicates that the harms of medical marijuana outweigh any purported benefit.

There is no current evidence for validity of marijuana as a medicine. Drugs approved to treat medical conditions typically consist of one or two active compounds with a specified dosage and mechanism that have been rigorously tested for safety and efficacy. This is done in order to ensure that people are not harmed by ineffective or dangerous treatments. This standard must apply to any substance proposed as treatment for a medical condition, especially when that substance has so many documented and well-established risks at both the individual and population levels.