Dimethylheptylpyran

Dimethylheptylpyran (DMHP, 1,2-dimethylheptyl-Δ3THC) is a synthetic analogue of THC, which was invented in 1949 during attempts to elucidate the structure of Δ9-THC, the active component of cannabis.

DMHP is similar in both structure to THC, differing only in the position of one double bond, and the replacement of the 3-pentyl chain with a 3-(1,2-dimethylheptyl) chain. It produces similar activity to THC, such as sedative and antinauseant effects, but is considerably more potent. It is thought to act as a CB1 agonist, in a similar manner to other similar cannabinoid derivatives.

DMHP was made illegal under UN convention in 1982 on the basis of its structural similarity and similar effects profile to THC, despite never having had any recorded instances of abuse by humans or illicit sale. In the United States, DMHP was placed into the most restrictive Schedule 1 as a compound with no medical use, although it is still used in some scientific research into cannabinoid drugs.