On Friday the Food and Drug Administration launched its first hearing on Cannabidiol (CBD) products. CBD has become widely available in smoke shops and health food stores in tinctures, creams, seltzers and other products. The acting head of the FDA questioned how much CBD is safe to consume among other questions. The products have been purported to treat a number of ailments from inflammation to anxiety and insomnia. But what does the science tell us about CBD's effects on the brain and body?