Parahexyl (Synhexyl, n-hexyl-Δ3THC) is a synthetic homologue of THC, which was invented in 1949 during attempts to elucidate the structure of Δ9-THC, one of the active components of cannabis.
Parahexyl is similar in both structure and activity to THC, differing only in the position of one double bond, and the lengthening of the 3-pentyl chain by one CH2 group to n-hexyl.  Parahexyl produces classic cannabis agonist effects in animals. It has a somewhat higher oral bioavailability than THC itself but is otherwise very similar.  Presumably it acts as a CB1 agonist in the same way as THC but as there has been no research published using Parahexyl since the discovery of the CB1 receptor this has not been definitively confirmed.
Parahexyl 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. Parahexyl was placed into the most restrictive Schedule 1 as a compound with no medical use, even though it has never been properly researched to see whether it might have medical use or not.
- ↑ Adams R, Harfenist M, Loewe S (1949). [Expression error: Missing operand for > "New Analogs of Tetrahydrocannabinol. XIX"]. J. Am. Chem. Soc. 71 (5): 1624–1628. doi:10.1021/ja01173a023.
- ↑ Ask Dr. Shulgin Online March 7, 2001
- ↑ Ono M, Shimamine M, Takahashi K, Inoue T (1974). [Expression error: Missing operand for > "[Studies on hallucinogens. VII Synthesis of parahexyl]"] (in Japanese). Eisei Shikenjo hōkoku. Bulletin of National Institute of Hygienic Sciences 49 (92): 46–50. PMID 4477495.
- ↑ Fairchild MD, Jenden DJ, Mickey MR, Yale C (1980). [Expression error: Missing operand for > "EEG effects of hallucinogens and cannabinoids using sleep-waking behavior as baseline"]. Pharmacol. Biochem. Behav. 12 (1): 99–105. doi:10.1016/0091-3057(80)90422-0. PMID 6102770.
AM-883 • Arachidonyl-2'-chloroethylamide • Arachidonylcyclopropylamide • Methanandamide • O-585 • O-689 • O-1812 •O-1860 • O-1861