Cooper recently got funding from the National Institutes of Health for a study looking at cannabinoids — including CBD in isolation — as a substitute for opioids, and numerous other clinical trials of CBD are underway. It will be several years before results are available, but these studies should help clarify both what benefits the substance may provide and any side effects it may come with. Most of the adverse effects so far associated with cannabis, such as impairments in short-term memory, coordination and judgment,2 come from products that contain THC as well as CBD, Cooper said, but we need to do more studies to find out for sure whether CBD has fewer risks. Studies are also needed to identify the best way to administer and dose CBD. “I get emails from people asking me what dose of CBD to use, and the truth is, we really don’t know,” Cooper said.