Cannabis use for medicinal purposes dates back at least 3,000 years.[1-5] It was introduced into Western medicine in 1839 by W.B. O’Shaughnessy, a surgeon who learned of its medicinal properties while working in India for the British East India Company. Its use was promoted for reported analgesic, sedative, anti-inflammatory, antispasmodic, and anticonvulsant effects.

The cultivation of hemp in the EU is heavily weighted toward fiber production over oilseed production. In 1999, the EU produced about 27,000 t of hemp fiber, but only about 6,200 t of hemp seeds, mostly in France, and 90% of this was used as animal feed (Karus et al. 2000). The seeds (Fig. 33) have traditionally been employed as bird and poultry feed, but feeding the entire seeds to livestock has been considered to be a poor investment because of the high cost involved (although subsidization in Europe allows such usage, especially in France where hemp seeds are not legally permitted in human food). As pointed out later, higher yield and better harvesting practices may make whole hempseed an economical livestock feed. Moreover, seed cake left after expressing the oil is an excellent feed. Efforts are underway in Europe to add value in the form of processed products for hemp, especially cosmetics and food but, as noted below, the North American market is already quite advanced in oilseed applications.

This PDQ cancer information summary for health professionals provides comprehensive, peer-reviewed, evidence-based information about the use of Cannabis and cannabinoids in the treatment of people with cancer. It is intended as a resource to inform and assist clinicians who care for cancer patients. It does not provide formal guidelines or recommendations for making health care decisions.
Cement (Concrete) and Plaster. Utilizing the ancient technique of reinforcing clay with straw to produce reinforced bricks for constructing domiciles, plant fibers have found a number of comparable uses in modern times. Hemp fibers added to concrete increase tensile strength while reducing shrinkage and cracking. Whole houses have been made based on hemp fiber (Fig. 24, 25). In North America, such usage has only reached the level of a cottage industry. Fiber-reinforced cement boards and fiber-reinforced plaster are other occasionally produced experimental products. Hemp fibers are produced at much more cost than wood chips and straw from many other crops, so high-end applications requiring high strength seem most appropriate.

There is some speculation that George Washington smoked the flower of the cannabis plant in order to achieve a recreational high ("Like all farmers, Washington probably sampled the quality and potency of what he grew, and he may have used this hemp to treat his chronic tooth aches"),[53] but there is no evidence in any of his writings that he grew hemp for anything other than industrial purposes. It is sometimes supposed that an excerpt from Washington's diary, which reads "Began to seperate [sic] the Male from the Female hemp at Do.&—rather too late" is evidence that he was trying to grow female plants for the THC found in the flowers. However, the editorial remark accompanying the diary states that "This may arise from their [the male] being coarser, and the stalks larger"[115] In subsequent days, he describes soaking the hemp[116] (to make the fibers usable) and harvesting the seeds,[117] suggesting that he was growing hemp for industrial purposes, not recreational.
About half of the world market for hemp oil is currently used for food and food supplements (de Guzman 2001). For edible purposes, hempseed oil is extracted by cold pressing. Quality is improved by using only the first pressing, and minimizing the number of green seeds present. The oil varies in color from off-yellow to dark green. The taste is pleasantly nutty, sometimes with a touch of bitterness. Hemp oil is high in unsaturated fatty acids (of the order of 75%), which can easily oxidize, so it is unsuitable for frying or baking. The high degree of unsaturation is responsible for the extreme sensitivity to oxidative rancidity. The oil has a relatively short shelf life. It should be extracted under nitrogen (to prevent oxidation), protected from light by being kept in dark bottles, and from heat by refrigeration. Addition of anti-oxidants prolongs the longevity of the oil. Steam sterilization of the seeds, often required by law, allows air to penetrate and so stimulates rancidity. Accordingly, sterilized or roasted hemp seeds, and products made from hemp seed that have been subjected to cooking, should be fresh. The value of hemp oil from the point of view of the primary components is discussed below. In addition, it has been suggested that other components, including trace amounts of terpenes and cannabinoids, could have health benefits (Leizer et al. 2000). According to an ancient legend (Abel 1980), Buddha, the founder of Buddhism, survived a 6-year interval of asceticism by eating nothing but one hemp seed daily. This apocryphal story holds a germ of truth—hemp seed is astonishingly nutritional.
Marijuana, also called pot, weed, ganja, mary jane, and a host of other nicknames, is made from the Cannabis plant, which has three species: Cannabis sativa; Cannabis indica and Cannabis ruderalis. The flowering plant, which can grow to 16 feet (5 meters) high, likely originated in the Central Asian steppe, near the Altai or Tian Shian Mountains, and was first cultivated in China and India, according to "Cannabis and Cannabinoids: Pharmacology, Toxicology and Therapeutic Potential," (Routledge, 2002).
Marijuana or marihuana (herbal cannabis),[157] consists of the dried flowers and subtending leaves and stems of the female Cannabis plant.[158][159][160][161] This is the most widely consumed form,[161] containing 3% to 20% THC,[162] with reports of up-to 33% THC.[163] This is the stock material from which all other preparations are derived. Although herbal cannabis and industrial hemp derive from the same species and contain the psychoactive component (THC), they are distinct strains with unique biochemical compositions and uses. Hemp has lower concentrations of THC and higher concentrations of CBD, which decreases the psychoactive effects[164][165]
The main difference between the two is in its chemical composition, specifically in tetrahydrocannabinol (THC). THC is the chemical responsible marijuana’s psychological effects.An average batch of marijuana contains anywhere from 5-20% THC content. Some premium marijuana can have up to 25-30% THC. Hemp, on the other hand, has a max THC level of 0.3%, essentially making it impossible to feel any psychoactive effect or get a “high”. This threshold is heavily regulated in other countries that have legalized hemp.Hemp also has high cannabidiol (CBD) content that acts as THC’s antagonist, essentially making the minimal amount of THC useless.
Since the beginning of the 20th century, most countries have enacted laws against the cultivation, possession or transfer of cannabis.[209] These laws have impacted adversely on cannabis cultivation for non-recreational purposes, but there are many regions where handling of cannabis is legal or licensed. Many jurisdictions have lessened the penalties for possession of small quantities of cannabis so that it is punished by confiscation and sometimes a fine, rather than imprisonment, focusing more on those who traffic the drug on the black market.
Selection for fiber has resulted in strains that have much more bark fiber tissues and much less woody core than encountered in narcotic strains, oilseed strains, and wild plants (Fig. 12). In non-fiber strains of Cannabis, bark can be less than one quarter of the stem tissues (i.e. more than three quarters can be woody core). By contrast, in fiber strains half of the stem tissues can be bark, and more than half of this can be the desirable long primary fibers (de Meijer 1995). Non-fiber strains rarely have as much as 15% fiber in the bark.
^ Jump up to: a b c Whiting, PF; Wolff, RF; Deshpande, S; Di Nisio, M; Duffy, S; Hernandez, AV; Keurentjes, JC; Lang, S; Misso, K; Ryder, S; Schmidlkofer, S; Westwood, M; Kleijnen, J (23 June 2015). "Cannabinoids for Medical Use: A Systematic Review and Meta-analysis" (PDF). JAMA. 313 (24): 2456–2473. doi:10.1001/jama.2015.6358. hdl:10757/558499. PMID 26103030.
Sec. 7606. Legitimacy of Industrial Hemp Research contained in the 2014 Federal Farm Bill, which was signed into law Feb. 7, provides for the cultivation of industrial hemp for purposes of research by institutions of higher education or state departments of agriculture in states where it is legal. The interaction of the U.S. Drug Enforcement Agency (DEA) and the provisions of Sec. 7606 is a developing process. As TDA develops Tennessee's industrial hemp program every effort will be made to minimize the impact of federal law on potential hemp producers in Tennessee.   In May of 2016 the law was amended to allow for a processor license.
In 1976, Canadian botanist Ernest Small[65] and American taxonomist Arthur Cronquist published a taxonomic revision that recognizes a single species of Cannabis with two subspecies: C. sativa L. subsp. sativa, and C. sativa L. subsp. indica (Lam.) Small & Cronq.[61] The authors hypothesized that the two subspecies diverged primarily as a result of human selection; C. sativa subsp. sativa was presumably selected for traits that enhance fiber or seed production, whereas C. sativa subsp. indica was primarily selected for drug production. Within these two subspecies, Small and Cronquist described C. sativa L. subsp. sativa var. spontanea Vav. as a wild or escaped variety of low-intoxicant Cannabis, and C. sativa subsp. indica var. kafiristanica (Vav.) Small & Cronq. as a wild or escaped variety of the high-intoxicant type. This classification was based on several factors including interfertility, chromosome uniformity, chemotype, and numerical analysis of phenotypic characters.[51][61][66]
Hemp seeds can be eaten raw, ground into hemp meal, sprouted or made into dried sprout powder. The leaves of the hemp plant can be consumed raw in salads.[citation needed] Hemp seeds can also be made into a liquid and used for baking or for beverages such as hemp milk, hemp juice, and tea.[15] Hemp oil is cold-pressed from the seed and is high in unsaturated fatty acids.[16]