You should not use CBD oil if you are pregnant or breastfeeding. There is currently no reliable research on the effects of CBD oil on pregnant or breastfeeding women, so it’s best to avoid using it until more studies can be done.   Additionally, anyone with a history of alcoholism, drug abuse and mental illness should talk to their doctor before taking CBD oil. If you have heart disease or liver problems—or if you take prescription medications—you should also consult a doctor before trying CBD oil.