The side effect profile of CBD is as benign as any medication I can think of. In fact, in a comprehensive review of 132 studies, researchers found that CBD, at several different dosages, did not adversely affect vital signs, psychological function, motor function and did not produce toxic metabolites. However, there were no studies which surpassed dosages of over 1500mg/day. I do not recommend that you experiment with taking mega-doses of CBD, or anything for that matter.
Hope this helps!
There is no known lethal dose of CBD in humans. It has apparently been fatal in monkeys at a dose of 200 mg/kg, which for a normal male human would be about 14,000 mg. But I wouldn’t suggest trying to check it out. If you do take any prescription medications, 10,000 mg of CBD could be a sufficient dose to interefere with the metabolism of many of them. Otherwise, I’d mostly bet on some nausea and diarrhea. There are also essentially no reports of specific organ toxicity of CBD, but taking that much at one time of any biologically active substance could easily be toxic in ways that are not at all relevant in the reasonable dosage range.