For How Long Does CBD Last? Home › Forums › For How Long Does CBD Last? This topic has 1 reply, 2 voices, and was last updated 5 years, 8 months ago by dev7. Viewing 1 post (of 1 total) Author Posts March 3, 2019 at 3:42 am #1717 PrincessMMember The effects of CBD oil last from 4 to 6 hours. Author Posts Viewing 1 post (of 1 total) You must be logged in to reply to this topic. Log In Username: Password: Keep me signed in Log In