"The THC levels in industrial hemp are so low that no one can get high from smoking it. Moreover, industrial hemp, while low in THC, is high in another kind of cannabinoid, CBD, which counteracts THC’s psychoactivity.

"As William M. Pierce Jr., Ph.D., Associate Professor of Pharmacology and Toxicology at the University of Louisville School of Medicine notes, “Industrial hemp does in fact contain a psychoactive substance, tetrahydrocannabinol (THC) and thus the question appears at first reading to be a reasonable one. Upon closer consideration, however, using the most fundamental principles of pharmacology, it can be shown that it is absurd, in practical terms, to consider industrial hemp useful as a drug.”27

"According to Professor Pierce, to obtain a psychoactive effect with even 1 percent THC hemp (industrial hemp and feral hemp, the wild hemp the DEA aggressively harvests and burns28, contain less than 0.5% percent THC29 ), would require the user to smoke 10-12 cigarettes containing hemp in a “very short period of time. . . . This large volume (and) high temperature inhalation of vapor, gas, and smoke would be difficult for a person to withstand, much less enjoy.” Professor Pierce goes on to note that anyone who ate hemp hoping to get “high” would be consuming the fiber equivalent of several doses of a high-fiber laxative. In other words, the very unpleasant side effects would dissuade anyone from trying to use industrial hemp as a drug.

"Dr. Pierce points out that beer sold as “nonalcohol” contains measurable alcohol. So does mouthwash. Even nutmeg contains a psychoactive substance. But the authorities are not aggressively concerned about the abuse of these products because the side effects are so severe as to discourage such abuse.

"Critics have alleged that the marijuana of the sixties had THC levels comparable to those of industrial hemp. But when Lynn Zimmer, Ph.D., and John Morgan, M.D., examined this assertion they found it lacked substance."

Source

West, David P., PhD Hemp and Marijuana: Myths & Realities. North American Industrial Hemp Council, 1998.