"The information reviewed above indicates that cannabis has a long established history of efficacy in migraine treatment. Clinical use of the herb and its extracts for headache has waxed and waned for 1200 years, or perhaps much longer, in a sort of cannabis interruptus. It is only contemporaneously that supportive biochemical and pharmacological evidence for the indication is demonstrable. Cannabis’ unique ability to modulate various serotonergic receptor subtypes, inhibit glutamatergic-mediated toxicities, simultaneously provide antiinflammatory activity and provide acute symptomatic and chronic preventive relief make it unique among available treatments for this disorder."


Russo, Ethan, "Hemp for Headache: An In-Depth Historical and Scientific Review of Cannabis in Migraine Treatment," Journal of Cannabis Therapeutics (September 2000) Vol. 1, pp. 73-74.