CBD. CBD should not be confused with THC, since THC is not a legal substance in Spain, since it has a euphoric side effect that predisposes you. CBD oil with THC is only legal with a prescription from your doctor. However, it should be noted that there is currently no safe CBD oil without THC. However, the amount of THC seems so low that it has no effect and will not give you an euphoric side effect or a problem with the law.