In 1925 a compromise was made at an international conference in The Hague about the International Opium Convention that banned exportation of "Indian hemp" to countries that had prohibited its use, and requiring importing countries to issue certificates approving the importation and stating that the shipment was required "exclusively for medical or scientific purposes". It also required parties to "exercise an effective control of such a nature as to prevent the illicit international traffic in Indian hemp and especially in the resin".[199][200] In the United States in 1937, the Marihuana Tax Act was passed,[201] and prohibited the production of hemp in addition to cannabis.
It often takes 10 to 15 years for the industry associated with a new agricultural crop to mature. While it is true that foreign imports have been the basis for hemp products in North America for at least a decade, North American production is only 4 years of age in Canada, and farming of hemp in the US has not even begun. Viewed from this perspective, the hemp industry in North America is still very much in its infancy. Varieties of hemp specifically suited to given products and regions have only started to be developed in North America. There is considerable uncertainty regarding yields, costs of production, harvesting and processing equipment, product characteristics, foreign competition, governmental support, and the vagaries of the regulatory environment. Hemp is not presently a standard crop, and is likely to continue experiencing the risks inherent in a small niche market for some time. Hemp is currently a most uncertain crop, but has such a diversity of possible uses, is being promoted by extremely enthusiastic market developers, and attracts so much attention that it is likely to carve out a much larger share of the North American marketplace than its detractors are willing to concede.
In a randomized clinical trial, researchers compared the safety and effectiveness of orally administered Cannabis extract (2.5 mg THC and 1 mg CBD), THC (2.5 mg), or placebo for the treatment of cancer-related anorexia-cachexia in 243 patients with advanced cancer who received treatment twice daily for 6 weeks. Results demonstrated that although these agents were well tolerated by these patients, no differences were observed in patient appetite or quality of life among the three groups at this dose level and duration of intervention.[42]
Ten trials have evaluated the efficacy of inhaled Cannabis in chemotherapy-induced N/V.[35-38] In two of the studies, inhaled Cannabis was made available only after dronabinol failure. In the first trial, no antiemetic effect was achieved with marijuana in patients receiving cyclophosphamide or doxorubicin,[35] but in the second trial, a statistically significant superior antiemetic effect of inhaled Cannabis versus placebo was found among patients receiving high-dose methotrexate.[36] The third trial was a randomized, double-blind, placebo-controlled, crossover trial involving 20 adults in which both inhaled marijuana and oral THC were evaluated. One-quarter of the patients reported a favorable antiemetic response to the cannabinoid therapies. This latter study was reported in abstract form in 1984. A full report, detailing the methods and outcomes apparently has not been published, which limits a thorough interpretation of the significance of these findings.[37]
In 2015, almost half of the people in the United States had tried marijuana, 12% had used it in the past year, and 7.3% had used it in the past month.[31] In 2014, daily marijuana use amongst US college students had reached its highest level since records began in 1980, rising from 3.5% in 2007 to 5.9% in 2014 and had surpassed daily cigarette use.[239]
Industrial hemp is a versatile agricultural plant which could one day be a valuable crop option for Pennsylvania farmers. The Commonwealth of Pennsylvania has taken some important steps toward making that a reality. Following Governor Wolf’s signing of the Industrial Hemp Research Act, Number 92 in 2016, the Pennsylvania Department of Agriculture’s Industrial Hemp Research Pilot Program started issuing permits for research & growth of industrial hemp in 2017. Pennsylvania’s industrial hemp legislation was sparked by the passage of the 2014 Farm Bill, which gave federal permission for institutions of higher education or state Departments of Agriculture to research the cultivation and marketing of industrial hemp. As part of Pennsylvania’s Research Pilot Program, industrial hemp was legally grown in the Commonwealth after an 80 years hiatus. The Department of Agriculture has issued 35 research permits in the last two years to institutions of higher education and to farmers, business or individuals in contract with the Department to participate in the research of industrial hemp cultivation and marketing in Pennsylvania. In 2018, 35 research permits were issued to researchers, who cultivated industrial hemp in 25 Pennsylvania counties. 
We gave the highest points to companies that use a CBD distillate for their tinctures. The process of distillation creates an extract that is pure on a molecular level. There are people who think distillate is too pure, and that a full spectrum decarb produces a more effective tincture. But in light of the inconclusive evidence, we prefer a distillate. The process allows for a high degree of control as to the finished product. It’s also odorless and tasteless, so those tinctures tend to taste better.
The world-leading producer of hemp is China, which produces more than 70% of the world output. France ranks second with about a quarter of the world production. Smaller production occurs in the rest of Europe, Chile, and North Korea. Over 30 countries produce industrial hemp, including Australia, Austria, Canada, Chile, China, Denmark, Egypt, Finland, Great Britain, Germany, Greece,[64] Hungary, India, Italy, Japan, Korea, Netherlands, New Zealand, Poland, Portugal, Romania, Russia, Slovenia, Spain, Sweden, Switzerland, Thailand, Turkey and Ukraine.[65][66]
The above uses are based on hemp as a mechanical strengthener of materials. Hemp can also be chemically combined with materials. For example, hemp with gypsum and binding agents may produce light panels that might compete with drywall. Hemp and lime mixtures make a high quality plaster. Hemp hurds are rich in silica (which occurs naturally in sand and flint), and the hurds mixed with lime undergo mineralization, to produce a stone-like material. The technology is most advanced in France (Fig. 26). The mineralized material can be blown or poured into the cavities of walls and in attics as insulation. The foundations, walls, floors, and ceilings of houses have been made using hemp hurds mixed with natural lime and water. Sometimes plaster of Paris (pure gypsum), cement, or sand is added. The resulting material can be poured like concrete, but has a texture vaguely reminiscent of cork—much lighter than cement, and with better heat and sound-insulating properties. An experimental “ceramic tile” made of hemp has recently been produced (Fig. 27).

Two studies examined the effects of oral delta-9-THC on cancer pain. The first, a double-blind, placebo-controlled study involving ten patients, measured both pain intensity and pain relief.[50] It was reported that 15 mg and 20 mg doses of the cannabinoid delta-9-THC were associated with substantial analgesic effects, with antiemetic effects and appetite stimulation.
"The data supporting efficacy and dosing are specific to one product: Epidiolex," Bonn-Miller says. "That's not necessarily translatable to 'Joe Bob's CBD Blend.'" A CBD extract you buy online or in a dispensary will almost certainly have less CBD in it, he explains, and will contain other cannabinoids—meaning that it will work differently and will need to be dosed differently. "This is not to say that 'Joe Bob's CBD Blend' definitely isn't going to be effective for pediatric epilepsy, but it means that we need to study it before we know."
Hemp is possibly one of the earliest plants to be cultivated.[102][103] An archeological site in the Oki Islands near Japan contained cannabis achenes from about 8000 BC, probably signifying use of the plant.[104] Hemp use archaeologically dates back to the Neolithic Age in China, with hemp fiber imprints found on Yangshao culture pottery dating from the 5th millennium BC.[101][105] The Chinese later used hemp to make clothes, shoes, ropes, and an early form of paper.[101] The classical Greek historian Herodotus (ca. 480 BC) reported that the inhabitants of Scythia would often inhale the vapors of hemp-seed smoke, both as ritual and for their own pleasurable recreation.[106]

There are new CBD companies coming online every week – these span the range from truly awful to really great. So how to choose the best? The quality of the CBD oil itself is obviously the most important factor – and many companies do take the quality of their products seriously. To reward those companies, we gave more weight to the quality of the product than any other category.
Hemp is used to make a variety of commercial and industrial products including rope, textiles, clothing, shoes, food, paper, bioplastics, insulation, and biofuel.[5] The bast fibers can be used to make textiles that are 100% hemp, but they are commonly blended with other fibers, such as flax, cotton or silk, as well as virgin and recycled polyester, to make woven fabrics for apparel and furnishings. The inner two fibers of the plant are more woody and typically have industrial applications, such as mulch, animal bedding and litter. When oxidized (often erroneously referred to as "drying"), hemp oil from the seeds becomes solid and can be used in the manufacture of oil-based paints, in creams as a moisturizing agent, for cooking, and in plastics. Hemp seeds have been used in bird feed mix as well.[13] A survey in 2003 showed that more than 95% of hemp seed sold in the European Union was used in animal and bird feed.[14]