Even though CBD has a good safety profile, if you are taking medication, you should check with your doctor before trying it, however unfortunately most doctors are not familiar with the use of CBD. Both CBD and most pharmaceuticals are detoxified by the liver’s cytochrome P450 enzyme system. As a result, certain medications, including chemotherapy agents, anti-epilepsy drugs, and the blood thinner coumadin may be affected. For a list of potential drugs that may interact with CBD, see resources below. The fact is, though, we have found that doses under 100 mg a day generally do not interfere with medications. For a list of medications that may interact with CBD, check this list by Penn State College of Medicine.