Considered the most scientific method this is also among the cleanest techniques of extraction. Referred to as sub-critical or super critical CO² method, it uses carbon dioxide under different pressures to extract the medicinal oil. This is among the most expensive techniques of extraction due to use of hi-tech equipment that can be operated by trained personnel only. The advantage of this technique is that the end product is the purest form of CBD oil which is highly potent and free of chlorophyll. However if the heat used during extraction is too high it can damage terpenes in the oil that have therapeutic benefits and provide flavor and essence to the oil strain.
Scott Shannon, M.D., assistant clinical professor at the University of Colorado, recently sifted through patient charts from his four-doctor practice to document CBD’s effects on anxiety. His study, as yet unpublished, found “a fairly rapid decrease in anxiety scores that appears to persist for months,” he says. But he says he can’t discount a placebo effect, especially since “there’s a lot of hype right now.”