CBD capsules have a negligible THC concentration so they should not cause any excess drowsiness or sleepiness. Having said that, CBD is well-known for having a relaxing effect, reducing anxiety and boosting serotonin production so there is potential that if the user is already tired, they may then feel relaxed or 'chilled' enough to go to sleep. For this reason, some people who are struggling with sleep or insomnia may contemplate using CBD products before bedtime to help them get to sleep.