In Canada, the methodology used for analyses and sample collection for THC analysis of hemp plantings is standardized (at the Health Canada/Therapeutics Program/Hemp web site at www.hc-sc.gc.ca/hpb-dgps/therapeut/htmleng/hemp.html, see “Industrial Hemp Technical Manual” for procedures on sampling plant materials and chemical procedures for determining THC levels). The regulations require that one of the dozen independent laboratories licensed for the purpose conduct the analyses and report the results to Health Canada. Sample collection is also normally carried out by an independent authorized firm. The Canadian system of monitoring THC content has rigidly limited hemp cultivation to cultivars that consistently develop THC levels below 0.3%.
A CNN program that featured Charlotte's Web cannabis in 2013 brought increased attention to the use of CBD in the treatment of seizure disorders. Since then, 16 states have passed laws to allow the use of CBD products with a doctor's recommendation (instead of a prescription) for treatment of certain medical conditions. This is in addition to the 30 states that have passed comprehensive medical cannabis laws, which allow for the use of cannabis products with no restrictions on THC content. Of these 30 states, eight have legalized the use and sale of cannabis products without requirement for a doctor's recommendation.
^ Jump up to: a b Weinstein A, Livny A, Weizman A (2016). "Brain Imaging Studies on the Cognitive, Pharmacological and Neurobiological Effects of Cannabis in Humans: Evidence from Studies of Adult Users". Current Pharmaceutical Design. 22 (42): 6366–6379. doi:10.2174/1381612822666160822151323. PMID 27549374. 1)The studies reviewed so far demonstrated that chronic cannabis use has been associated with a volume reduction of the hippocampus...3)The overall conclusion arising from these studies is that recent cannabis users may experience subtle neurophysiological deficits while performing on working memory tasks, and that they compensate for these deficits by "working harder" by using additional brain regions to meet the demands of the task.
To this point, CBD oil has existed in a kind of liminal space— at once an illegal drug, a legal medication, and some kind of “dietary” supplement. It’s possible this could change in the coming years, however. GW Pharmaceuticals, a U.K.-based firm, has developed a “pure CBD” medication called Epidiolex that has shown promising test results. It is currently on a fast-track to receive FDA clearance. For some patients, Epidiolex could be a miracle cure. This summer, in Wired magazine, writer Fred Vogelstein chronicled his family’s own struggles to find an effective treatment for his son’s epilepsy—including experiments with hemp oil— and the immense hurdles they overcame to gain access to Epidiolex prior to its FDA approval. The drug could be for sale on pharmacy shelves in the near future, though exactly how near is hard to say.
The scientific debate regarding taxonomy has had little effect on the terminology in widespread use among cultivators and users of drug-type Cannabis. Cannabis aficionados recognize three distinct types based on such factors as morphology, native range, aroma, and subjective psychoactive characteristics. Sativa is the most widespread variety, which is usually tall, laxly branched, and found in warm lowland regions. Indica designates shorter, bushier plants adapted to cooler climates and highland environments. Ruderalis is the informal name for the short plants that grow wild in Europe and Central Asia.