How Much THC is Needed For Sleep Help? Home › Forums › How Much THC is Needed For Sleep Help? This topic has 0 replies, 1 voice, and was last updated 6 years, 2 months ago by Liz S. Viewing 1 post (of 1 total) Author Posts March 3, 2019 at 2:13 am #1716 Liz SMember 20 milligrams of THC is optimal for sleep, with a ratio of 20:0, meaning that it is 20 parts of THC to 0 of CBD. This means the oil has mainly THC in it. 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