Surprisingly, the toxic dose is said to be at 20,000 mg of CBD. But even then, CBD is not lethal. According to the World Health Organization, even in extremely high doses, CBD will probably make you lazy, fatigued, and cause other uncomfortable side effects including diarrhea and nausea but not death. The World Health Organization also states that CBD is one of the few substances we know of that have zero major side effects and doesn’t come with a risk of addiction.