Dr. Ryan Vandrey, of Johns Hopkins University, joins us to discuss the best routes of administration for different conditions. For example, when treating chronic pain, oral administration is preferable, as it yields a more sustained drug effect. However, with a symptom like nausea, inhalation would likely be the preferred route of administration, as eating or drinking may aggravate the nausea. As well, Vandrey talks about the flawed methods of testing THC levels in blood: "If we take somebody who uses cannabis frequently and they don't use for 24 hours, they have as much THC in their blood as the person who's eating a 50-milligram edible and is highly impaired. So, blood THC levels are incredibly complicated. What you have is a high likelihood of erroneous assumptions based on blood THC levels."