Cannabis use–both recreationally and as a medicinal product–is a controversial topic. So what does it really do? Dr. William Sauvé discusses the widespread role of the endocannabinoid system, and the potential effects—both positive and negative—of exogenous cannabinoids on the body and brain. Originally presented at the 2016 NEI Congress. NEI Members can view the full presentation at http://www.neiglobal.com/Members/Encore/EncHldrM/tabid/495/action/case/args/CT_AT-ENC16-16CNG-19/Default.aspx.