The World Health Organization (WHO) recently announced that it deems CBD to be safe and based their ruling on an internal study which includes the medical benefits of CBD. In addition to ruling that CBD is indeed effective, the study concluded that there was no addiction risk involved with the use of CBD.
While uncommon, some CBD users have reported some of the potential side effects below (some due to using lower quality CBD, the purity and source matters!)
Low blood pressure when taking high doses of CBD.
Lightheadedness when taking high doses of CBD.
Drowsiness when taking high doses of CBD.