Two isomers of THCA have been discovered, 2-COOH-THC (THCA-A) and 4-COOH-THC (THCA-B) (Fig. Cannabis primarily biosynthesizes THCA-A, 1 and this isomer has been the focus of most pharmacological studies. In the world of cannabis, a THC isomer generally refers to a variant of THC that manufacturers have chemically modified to produce at higher concentrations. These variants, such as delta-8 and delta-10, have the same chemical formula as delta-9 THC, but with a different atomic structure.
Little is known about how delta-6 THC affects human patients, but it is the latest in a series of rare THC isomers that are produced from hemp precursors. Products containing rare THC isomers produced from hemp do not have to be tested and are not regulated, as are products containing delta-9 THC manufactured in state-authorized facilities. The most recent extension of this trend seems to be the isolation (or isomerization to create) new and rare isomers of tetrahydrocannabinol (THC) for inclusion in new consumer products. Products made with these rare THC isomers must also undergo basic safety tests (against contaminants and solvents) and purity tests for all the cannabinoids in the products, especially in the case of delta-10 products, which usually contain significant amounts of delta-8 THC or delta-9 THC.