The inability to make reliable assertions about marijuana based on research on its constituent parts is a recurring theme in DEA's rejection of an Administrative Law Judge recommendation that marijuana has accepted medical use in the United States. Here are eight examples.

"Although delta-9-THC is an active ingredient in the marijuana plant material, marijuana contains over 400 other chemicals. At least 61 of these chemicals are cannabinoids. All these chemicals could have some effect on the human body. Since THC is only one of many active ingredients in marijuana, THC studies are of very limited value in evaluating the therapeutic utility of marijuana."(2)

"THC is only one constituent among hundreds found in marijuana. Therefore, the consequences of an individual ingesting pure THC as compared to smoking marijuana are vastly different."(3)

"Twenty-one cannabinoids have been clinically evaluated. Most of this testing centered on the psychotropic effects of the compounds, and only eight or nine of the cannabinoids have been tested for therapeutic utility. These studies have only been cursory except for the testing of synthetic THC. Cannabigerol (CBG) cannabinoids show antibacterial activity against gram positive bacteria, and have been shown to effect basic cell metabolism. Cannabinol (CBN) type compounds have exhibited anticonvulsant, anti-inflammatory, immunological, and behavioral effects. CBN has also exhibited possible potentiation of THC effects in man. Cannabidiol (CBD) has exhibited anticonvulsant activity."(4)

"As well as significant variations in naturally occurring substances in natural cannabis, there are variations in the active substances based on conditions under which the plant material has been maintained or stored. THC is labile (sic) to air oxidation forming cannabinol (CBN). Cannabidiol (CBD), in the presence of oxygen and light and upon heating, is converted to cannabielsoic acids."(5)

"Although THC is usually a constituent present in marijuana, since marijuana also contains at least 60 other active cannabinoids in varying quantities, the results of antiemetic trials using THC cannot be extrapolated in evaluating marijuana's antiemetic properties. For example, cannabidiol, a constituent present in marijuana, can potentiate some effects of THC, while suppressing other effects, including the antiemetic effect."(6)

"Most pharmacological research with cannabis or its constituents has actually been conducted with orally ingested THC, rather than smoked marijuana. Although the pharmacologic effects are presumed to be similar, the studies with oral THC do not provide a complete picture of marijuana's effects. Few of the other cannabinoids have been pharmacologically evaluated. The health consequences from smoking marijuana are likely to be quite different than those of orally ingested THC. Yet most of the chronic animal studies have been conducted with oral or intravenous THC."(7)

"The effect of taking a drug in combination with other chemicals is seldom the same as taking just the pure drug."(8)

"[M]arijuana's chemistry is neither fully known, nor reproducible. Thus far, over 400 different chemicals have been identified in the plant. The proportions and concentrations differ from plant to plant, depending on growing conditions, age of the plant, harvesting and storage factors. THC levels can vary from less than 0.2% to over 10%. It is not known how smoking or burning the plant material affects the composition of all these chemicals. It is not possible to reproduce the drug in dosages which can be considered standardized by any currently accepted scientific criteria."(9)