Human pharmacology of 1S and 1R enantiomers of delta-3-tetrahydrocannabinol.

Two enantiomers (1S and 1R) of delta-3-tetrahydrocannabinol were assayed in man for psychoactivity. The 1S enantiomer had definite psychic actions, qualitatively similar to those of delta-1-tetrahydrocannabinol, but quantitatively less potent (1:3 to 1:6). Adding the two enantiomers together did not increase the effect, confirming that activity was solely in the one enantiomer and that there was no interaction between them.