Many monoecious varieties have also been described,[19] in which individual plants bear both male and female flowers.[20] (Although monoecious plants are often referred to as "hermaphrodites", true hermaphrodites – which are less common in Cannabis – bear staminate and pistillate structures together on individual flowers, whereas monoecious plants bear male and female flowers at different locations on the same plant.) Subdioecy (the occurrence of monoecious individuals and dioecious individuals within the same population) is widespread.[21][22][23] Many populations have been described as sexually labile.[24][25][26]
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]

Cannabis, also known as marijuana among other names,[n 1] is a psychoactive drug from the Cannabis plant used for medical or recreational purposes.[16][17][18] The main psychoactive part of cannabis is tetrahydrocannabinol (THC), one of 483 known compounds in the plant,[19] including at least 65 other cannabinoids.[20] Cannabis can be used by smoking, vaporizing, within food, or as an extract.[21]
Cannabis contains a seemingly unique class of chemicals, the cannabinoids, of which more than 60 have been described, but only a few are psychoactive. Cannabinoids are produced in specialized epidermal glands, which differ notably in distribution on different organs of the plant (high concentrations occur on the upper surface of the young leaves and young twigs, on the tepals, stamens, and especially on the perigonal bract). Given this distribution, the glands would seem to be protective of young and reproductive above-ground tissues (the roots lack glands). Two classes of epidermal glands occur—stalked and sessile (Fig. 8), but in either case the glandular cells are covered by a sheath under which resin is accumulated, until the sheath ruptures, releasing resin on the surface. The resin is a sticky mixture of cannabinoids and a variety of terpenes. The characteristic odor of the plant is due to the abundant terpenes, which are not psychoactive. The more important cannabinoids are shown in Fig. 9. In the plant the cannabinoids exist predominantly in the form of carboxylic acids, which decarboxylate with time or when heated. Delta-9-tetrahydrocannabinol (D9-THC, or simply THC) is the predominant psychoactive component. Other THC isomers also occur, particularly D8-THC, which is also psychoactive. Technically, the euphoric psychological effects of THC are best described by the word psychotomimetic. Cannabidiol (CBD) is the chief non-psychotomimetic cannabinoid. A THC concentration in marijuana of approximately 0.9% has been suggested as a practical minimum level to achieve the (illegal) intoxicant effect, but CBD (the predominant cannabinoid of fiber and oilseed varieties) antagonizes (i.e. reduces) the effects of THC (Grotenhermen and Karus 1998). Concentrations of 0.3% to 0.9% are considered to have “only a small drug potential” (Grotenhermen and Karus 1998). Some cannabinoid races have been described, notably containing cannabichromene (particularly in high-THC forms) and cannabigerol monomethyl ether (in some Asian strains). The biosynthetic pathways of the cannabinoids are not yet satisfactorily elucidated, although the scheme shown in Fig. 10 is commonly accepted. At least in some strains, THC is derived from cannabigerol, while in others it may be derived from CBD. CBN and D8-THC are considered to be degradation products or analytical artifacts (Pate 1998a).
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]
Short-term use of the drug impairs thinking and coordination. In long-term studies, teens who smoke marijuana have lower IQs later on, as well as structural differences in their brains, though scientists debate whether this is an effect of the drug or a result of habitual pot smokers seeking out less intellectually stimulating pursuits. A 2016 study on almost 300 students by the University of Montreal published in the journal Development and Psychopathology found that teens who start smoking around age 14 do worse on some cognitive tests by age 20 than non-smokers. They also have a higher school dropout rate. If they wait until age 17 to start, though, the smokers do not seem to have the same impairments, according to the study. 

One of the most curious uses of hemp is as a fence to prevent pollen transfer in commercial production of seeds. Isolation distances for ensuring that seeds produced are pure are considerable for many plants, and often impractical. At one point in the 1980s, the only permitted use of hemp in Germany was as a fence or hedge to prevent plots of beets being used for seed production from being contaminated by pollen from ruderal beets. The high and rather inpenetrable hedge that hemp can produce was considered unsurpassed by any other species for the purpose. As well, the sticky leaves of hemp were thought to trap pollen. However, Saeglitz et al. (2000) demonstrated that the spread of beet pollen is not effectively prevented by hemp hedges. Fiber (i.e. tall) cultivars of hemp were also once used in Europe as wind-breaks, protecting vulnerable crops against wind damage. Although hemp plants can lodge, on the whole very tall hemp is remarkably resistant against wind.
Research suggests that CBD may exert some of its pharmacological action through its inhibition of fatty acid amide hydrolase (FAAH), which may in turn increase the levels of endocannabinoids, such as anandamide, produced by the body.[8] It has also been speculated that some of the metabolites of CBD have pharmacological effects that contribute to the biological activity of CBD.[43]
Fig. 11. Frequency histograms of THC concentration in germplasm collections. Left, collection of E. Small and D. Marcus; of the 167 accessions, 43% had THC levels >0.3%. Right, the collection of the Vavilov Institute, St. Petersburg; of the 278 accessions for which chemical analyses were reported in Anonymous (1975), about 55% had THC levels >0.3%.
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.
To make matters more confusing, nine states (including California, Washington, and Colorado) let residents buy cannabis-based products with or without THC. Nearly two dozen other “medical marijuana states” allow the sale of cannabis, including capsules, tinctures, and other items containing CBD or THC, at licensed dispensaries to people whose doctors have certified that they have an approved condition (the list varies by state but includes chronic pain, PTSD, cancer, autism, Crohn’s disease, and multiple sclerosis). Sixteen more states legalized CBD for certain diseases. But because all these products are illegal according to the federal government, cannabis advocates are cautious. “By and large, the federal government is looking the other way,” says Paul Armentano, deputy director of the Washington, DC–based National Organization for the Reform of Marijuana Laws (NORML), but until federal laws are changed, “this administration or a future one could crack down on people who produce, manufacture, or use CBD, and the law would be on its side.”

Cannabis was criminalized in various countries beginning in the 19th century. The British colonies of Mauritius banned cannabis in 1840 over concerns on its effect on Indian indentured workers;[194] the same occurred in British Singapore in 1870.[195] In the United States, the first restrictions on sale of cannabis came in 1906 (in District of Columbia).[196] It was outlawed in Jamaica (then a British colony) in 1913, in South Africa in 1922, and in the United Kingdom and New Zealand in the 1920s.[197] Canada criminalized cannabis in The Opium and Narcotic Drug Act, 1923,[198] before any reports of the use of the drug in Canada, but eventually legalized its consumption for recreational and medicinal purposes in 2018.[37]

Can CBD oil help anxiety? Cannabidiol (CBD) is a chemical occurring in cannabis plants. It is possible to add CBD oil to food, and an increasing amount of evidence suggests that it may improve mental health, particularly anxiety. It does not seem to have adverse side effects, but CBD oil is illegal in some states. Learn more about CBD oil here. Read now
Professors William Emboden, Loran Anderson, and Harvard botanist Richard E. Schultes and coworkers also conducted taxonomic studies of Cannabis in the 1970s, and concluded that stable morphological differences exist that support recognition of at least three species, C. sativa, C. indica, and C. ruderalis.[67][68][69][70] For Schultes, this was a reversal of his previous interpretation that Cannabis is monotypic, with only a single species.[71] According to Schultes' and Anderson's descriptions, C. sativa is tall and laxly branched with relatively narrow leaflets, C. indica is shorter, conical in shape, and has relatively wide leaflets, and C. ruderalis is short, branchless, and grows wild in Central Asia. This taxonomic interpretation was embraced by Cannabis aficionados who commonly distinguish narrow-leafed "sativa" strains from wide-leafed "indica" strains.[72]
It has been contended that hemp is notably superior to most crops in terms of biomass production, but van der Werf (1994b) noted that the annual dry matter yield of hemp (rarely approaching 20 t/ha) is not exceptional compared to maize, beet, or potato. Nevertheless, hemp has been rated on a variety of criteria as one of the best crops available to produce energy in Europe (Biewinga and van der Bijl 1996). Hemp, especially the hurds, can be burned as is or processed into charcoal, methanol, methane, or gasoline through pyrolysis (destructive distillation). As with maize, hemp can also be used to create ethanol. However, hemp for such biomass purposes is a doubtful venture in North America. Conversion of hemp biomass into fuel or alcohol is impractical on this continent, where there are abundant supplies of wood, and energy can be produced relatively cheaply from a variety of sources. Mallik et al. (1990) studied the possibility of using hemp for “biogas” (i.e. methane) production, and concluded that it was unsuitable for this purpose. Pinfold Consulting (1998) concluded that while there may be some potential for hemp biomass fuel near areas where hemp is cultivated, “a fuel ethanol industry is not expected to develop based on hemp.”
This may be a good place to point out that not all CBD products are created equal. The industry is still largely unregulated, and the quality and quantity of CBD in a given product will vary wildly. Third party testing definitely helps to monitor companies’ claims, but it’s still up to you as the consumer to do your homework on the best CBD products.
Newer antiemetics (e.g., 5-HT3 receptor antagonists) have not been directly compared with Cannabis or cannabinoids in cancer patients. However, the Cannabis-extract oromucosal spray, nabiximols, formulated with 1:1 THC:CBD was shown in a small pilot randomized, placebo-controlled, double-blinded clinical trial in Spain to treat chemotherapy-related N/V.[39][Level of evidence: 1iC] ASCO antiemetic guidelines updated in 2017 states that evidence remains insufficient to recommend medical marijuana for either the prevention or treatment of N/V in patients with cancer who receive chemotherapy or radiation therapy.[30]

Karl W. Hillig, a graduate student in the laboratory of long-time Cannabis researcher Paul G. Mahlberg[77] at Indiana University, conducted a systematic investigation of genetic, morphological, and chemotaxonomic variation among 157 Cannabis accessions of known geographic origin, including fiber, drug, and feral populations. In 2004, Hillig and Mahlberg published a chemotaxonomic analysis of cannabinoid variation in their Cannabis germplasm collection. They used gas chromatography to determine cannabinoid content and to infer allele frequencies of the gene that controls CBD and THC production within the studied populations, and concluded that the patterns of cannabinoid variation support recognition of C. sativa and C. indica as separate species, but not C. ruderalis.[52] The authors assigned fiber/seed landraces and feral populations from Europe, Central Asia, and Turkey to C. sativa. Narrow-leaflet and wide-leaflet drug accessions, southern and eastern Asian hemp accessions, and feral Himalayan populations were assigned to C. indica. In 2005, Hillig published a genetic analysis of the same set of accessions (this paper was the first in the series, but was delayed in publication), and proposed a three-species classification, recognizing C. sativa, C. indica, and (tentatively) C. ruderalis.[55] In his doctoral dissertation published the same year, Hillig stated that principal components analysis of phenotypic (morphological) traits failed to differentiate the putative species, but that canonical variates analysis resulted in a high degree of discrimination of the putative species and infraspecific taxa.[78] Another paper in the series on chemotaxonomic variation in the terpenoid content of the essential oil of Cannabis revealed that several wide-leaflet drug strains in the collection had relatively high levels of certain sesquiterpene alcohols, including guaiol and isomers of eudesmol, that set them apart from the other putative taxa.[79] Hillig concluded that the patterns of genetic, morphological, and chemotaxonomic variation support recognition of C. sativa and C. indica as separate species. He also concluded there is little support to treat C. ruderalis as a separate species from C. sativa at this time, but more research on wild and weedy populations is needed because they were underrepresented in their collection.


It’s also worth noting that more and more people now use cannabis for medicinal purposes, as it is known to offer pain relief for some chronic conditions, as well as stimulate the appetite for people who are sick and may not feel like eating (such as cancer patients undergoing chemotherapy). Despite evidence that cannabis has medical benefits, you should always discuss your options for medical treatment with your doctor and use medical cannabis under their supervision.
You then take your first drop of CBD oil, wait 45 minutes, then ask the questions again. If you feel no different and there’s no change in the way you answer those questions, you increase the dose by small increments until you do notice a difference. You can continue this process over several days – and at some point, you’ll find that taking more doesn’t change your scores. That is your minimum effective dose.
Van Roekel (1994) has pointed out that Egyptian papyrus sheets are not “paper,” because the fiber strands are woven, not “wet-laid;” the oldest surviving paper is over 2,000 years of age, from China, and was made from hemp fiber (Fleming and Clarke 1998). Until the early 19th century, hemp, and flax were the chief paper-making materials. In historical times, hemp rag was processed into paper. Using hemp directly for paper was considered too expensive, and in any event the demand for paper was far more limited than today. Wood-based paper came into use when mechanical and chemical pulping was developed in the mid 1800s in Germany and England. Today, at least 95% of paper is made from wood pulp.
"CBD increases the circulating levels of your natural endocannabinoids, which, in turn, interact with your cannabinoid receptors," Bonn-Miller says. "CBD has also been shown to interact with serotonin receptors, and that may be part of why it has some beneficial effects on anxiety. It also interacts with some pain receptors, which may be why we're starting to see effects on pain and inflammation."
Concerned about Mykayla’s stomach cramps, Krenzler, who lives in Portland, Oregon, sent a sample of the oil off to Going Green Labs in Albany, Oregon. Like most labs catering to the cannabis industry, Going Green mainly performs THC potency tests. According to Krenzler, when the lab tested his sample, it found that the Real Scientific Hemp Oil contained much more THC than HempMedsPx had claimed—3.8 percent, instead of roughly 1 percent. Krenzler said he was “disturbed” by the finding, and also by the implications it had for other parents of sick children. Medical marijuana is legal in Oregon, but Krenzler noted that in other states that have not legalized pot, anyone purchasing a product with more than a trace amount of THC could find themselves in legal jeopardy. “I feel that HempMeds had misrepresented their product,” Krenzler said.
Researchers in New Zealand have studied whether cannabis can be used to treat severe motor and vocal tics in those suffering from Tourette syndrome. The study concluded that subjects who took a controlled THC-CBD medicated spray showed marked improvement in the frequency and severity of motor and vocal tics post-treatment. Although the study is only a small clinical trial, it is one of the first to specifically analyze the effects of cannabis on Tourette syndrome.
The opportunity to grow a new specialty oilseed crop in Kansas offers potential for diversification for Kansas farmers looking for an alternative crop, or for new farming enterprises interested in cultivating industrial hemp. The Kansas agriculture industry has developed a statewide strategic growth plan in recent years, and is committed to pursuing new and innovative opportunities to grow agriculture. The research generated by participants of this new industrial hemp program will be valuable data in identifying the growth potential offered in this sector.
PDQ is a registered trademark. Although the content of PDQ documents can be used freely as text, it cannot be identified as an NCI PDQ cancer information summary unless it is presented in its entirety and is regularly updated. However, an author would be permitted to write a sentence such as “NCI’s PDQ cancer information summary about breast cancer prevention states the risks succinctly: [include excerpt from the summary].”
In Europe and Asia, hemp farming has been conducted for millennia. Although most countries ceased growing hemp after the second word war, some didn’t, including France, China, Russia, and Hungary, so that essential knowledge of how to grow and process hemp was maintained. When commercial hemp cultivation resumed in Canada in 1997, many farmers undertook to grow the crop without appreciating its suitability for their situation, or for the hazards of an undeveloped market. Hemp was often grown on farms with marginal incomes in the hopes that it was a savior from a downward financial spiral. The myth that hemp is a wonder crop that can be grown on any soil led some to cultivate on soils with a history of producing poor crops; of course, a poor crop was the result.
Do not use cannabis if you are pregnant or could become pregnant. There is some evidence that women who smoke cannabis during the time of conception or while pregnant may increase the risk of their child being born with birth defects. Pregnant women who continue to smoke cannabis are probably at greater risk of giving birth to low birthweight babies.
Though use of marijuana among Washington state youth has remained relatively stable over the last several years (see Healthy Youth Survey), youth perception of harm from use of marijuana has been steadily decreasing (meaning: fewer adolescents believe marijuana use is harmful). Marijuana is the second most-commonly used substance among 12th graders (alcohol is the first), with 27% of high school seniors reporting current (past 30-day) use.
A Cochrane meta-analysis of 23 randomized RCTs reviewed studies conducted between 1975 and 1991 that investigated dronabinol or nabilone, either as monotherapy or as an adjunct to the conventional dopamine antagonists that were the standard antiemetics at that time.[33] The chemotherapy regimens involved drugs with low, moderate, or high emetic potential. The meta-analysis graded the quality of evidence as low for most outcomes. The review concluded that individuals were more likely to report complete absence of N/V when they received cannabinoids compared with placebo, although they were more likely to withdraw from the study because of an adverse event. Individuals reported a higher preference for cannabinoids than placebo or prochlorperazine. There was no difference in the antiemetic effect of cannabinoids when compared with prochlorperazine. The authors concluded that Cannabis-based medications may be useful for treating refractory chemotherapy-induced N/V; however, they cautioned that their assessment may change with the availability of newer antiemetic regimens.
When oral Cannabis is ingested, there is a low (6%–20%) and variable oral bioavailability.[1,2] Peak plasma concentrations of delta-9-tetrahydrocannabinol (THC) occur after 1 to 6 hours and remain elevated with a terminal half-life of 20 to 30 hours. Taken by mouth, delta-9-THC is initially metabolized in the liver to 11-OH-THC, a potent psychoactive metabolite. Inhaled cannabinoids are rapidly absorbed into the bloodstream with a peak concentration in 2 to 10 minutes, declining rapidly for a period of 30 minutes and with less generation of the psychoactive 11-OH metabolite.
Cannabis was criminalized in various countries beginning in the 19th century. The British colonies of Mauritius banned cannabis in 1840 over concerns on its effect on Indian indentured workers;[194] the same occurred in British Singapore in 1870.[195] In the United States, the first restrictions on sale of cannabis came in 1906 (in District of Columbia).[196] It was outlawed in Jamaica (then a British colony) in 1913, in South Africa in 1922, and in the United Kingdom and New Zealand in the 1920s.[197] Canada criminalized cannabis in The Opium and Narcotic Drug Act, 1923,[198] before any reports of the use of the drug in Canada, but eventually legalized its consumption for recreational and medicinal purposes in 2018.[37]
In the United States, the public's perception of hemp as marijuana has blocked hemp from becoming a useful crop and product,"[52] in spite of its vital importance prior to World War II.[53] Ideally, according to Britain's Department for Environment, Food and Rural Affairs, the herb should be desiccated and harvested towards the end of flowering. This early cropping reduces the seed yield but improves the fiber yield and quality.[54] In these strains of industrial hemp* the tetrahydrocannabinol (THC) content would have been very low.[52]
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