THC acetates are semi-synthetic psychoactive cannabinoids obtained via acetylation of the cannabinoid phenol moiety. The acetylation reaction is analogous to that used for the transformation of morphine to heroin, to afford increased lipophilicity and blood brain barrier permeability. ∆ 9 -THC acetate (∆ -THC-OAc, or THCO in some sources, Figure ) had been investigated as an incapacitating agent by the US military as part of the Edgewood Arsenal experiments between 1949 and 1975 and was found to produce a two-fold greater degree of ataxia in dogs compared to ∆ 9 -THC. Recent anecdotal reports from users state that ∆ 9 -THC-OAc has significantly more psychoactive potency (ca. 300 % more) than THC. The legal status of ∆ 9 -THC-OAc is currently unclear. ∆ 8 -THC, an unregulated isomer of ∆ 9 -THC, along with its acetate derivative (∆ 8 -THC-OAc, Figure ), have become increasingly available, particularly in states where ∆ -THC is illegal. However, there is a lack of published peer-reviewed research concerning the cannabinoid acetates. The health risks of these compounds are currently unknown, despite their potency and ready availability.