When taken by mouth: Cannabidiol is POSSIBLY SAFE when taken by mouth or sprayed under the tongue appropriately. Cannabidiol in doses of up to 300 mg daily have been taken by mouth safely for up to 6 months. Higher doses of 1200-1500 mg daily have been taken by mouth safely for up to 4 weeks. A prescription cannabidiol product (Epidiolex) is approved to be taken by mouth in doses of up to 10-20 mg/kg daily. Cannabidiol sprays that are applied under the tongue have been used in doses of 2.5 mg for up to 2 weeks.
CBD and THC, of course, come from exactly the same plant, so it’s understandable why there’s likely to be some cross-contamination. A 2019 study found that 21% of CBD oils purchased online contain detectable amounts of THC, so if you are getting drug tested, taking CBD oil is not a good idea, especially given how long THC can remain in your system (13).
And now, onto the thorny issue of legality. The simple answer to the question is yes — if it is extracted from hemp. The 2014 Farm Bill established guidelines for growing hemp in the U.S. legally. This so-called “industrial hemp” refers to both hemp and hemp products which come from cannabis plants with less than 0.3 percent THC and are grown by a state-licensed farmer.