It can vary from person to person to figure out how long does CBD take to work. The onset of effects from CBD products depends on the form of CBD you’re using. The fastest onset of effects comes from inhaled forms of CBD (such as vapes or CBD flowers). Inhalation of CBD will result in benefits within 5 minutes, with the maximum effects reached in under 20 minutes. For oral forms of CBD, the onset times can range from 30 to 60 minutes.