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Cannabis has been used across continents for thousands of years for everything from pain relief to helping with sleep


Cannabis sativa Cannabaceae

Modern research is showing a wide variety of illnesses that can be treated with cannabis, because it works directly with our endocannabinoid system.

Sustainability Status

Sustainability status

Not currently on risk lists but complete data may be missing on the status of the species. Read more about our sustainability guide.

Key benefits
  • Anxiety
  • Sleep
  • Inflammation
  • Appetite
  • Pain
  • Epilepsy
  • How does it feel?

    Effects vary largely between people, and this is partially due to the phytochemical composition of the plant. For example a THC rich plant will cause stronger psychoactive effects. Common effects include feeling happy, giggly, sleepy however some people can feel paranoid and anxious.

  • What can I use it for?

    Cannabis’s use and potential spans across many different illnesses because it works directly with the endocannabinoid system. The endocannabinoid system acts as a “homeostatic warden” across the nervous system and immune system, which is why research shows the plant can have efficacy in illnesses ranging from mental health issues, inflammation, epilepsy and cancer.

    Many people use it for pain management, and it is often particularly favoured as an alternative to drugs like morphine for cancer patients. This is because of its favourable safety profile, as well as the fact that people remain mostly coherent, and appetite is increased.

    Cannabis is also used to help people with sleep as it has hypnotic effects. Commonly people use it for anxiety, however the plant also has a biphasic effect which means it can exacerbate symptoms if the dosage is wrong.

    Cannabis has also been shown to have remarkable effect on Parkinson’s disease. This is because THC works on the basal ganglia area of the brain, inhibiting motor neurons and stopping the tremors that can severely effect people’s quality of life.

  • Into the heart of cannabis

    Cannabis use dates back 8000 years, however it was only in 1928 due to its psychoactive effects.

    Now legislation is easing worldwide for both medical and recreational use. There has been massive scientific interest because the endocannabinoid was only discovered in 1992, which is only relatively recent in science terms.  The endocannabinoid mediates both the nervous system which is responsible for our thoughts, movement and emotions as well as the immune system. Cannabis binds directly to our endocannabinoid receptors, which is why it is so efficacious and hosts such a vast range of exciting medical potential.

  • Traditional uses

    Cannabis has been used across cultures for thousands of years. The first solid evidence of cannabis being used in India is about 10th century AD, according to Jan Meulenbeld who is a true scholar of Ayurvedic history.

    In Chinese medicine it is known as one of the 50 fundamental herbs and it is used for over 100 ailments, including gout and rheumatism. It was also used in ancient Greece, and has been cited in texts by Galen and Dioscorides.

  • Traditional actions

  • Traditional energetic actions

    Herbal energetics are the descriptions Herbalists have given to plants, mushrooms, lichens, foods, and some minerals based on the direct experience of how they taste, feel, and work in the body. All traditional health systems use these principles to explain how the environment we live in and absorb, impacts our health. Find out more about traditional energetic actions in our article “An introduction to herbal energetics“.

  • What practitioners say

    There is some controversy amongst practitioners about the use of medical cannabis, and given its legal history and potential side effects this debate is to be expected. However, there are many doctors, specialists and scientists who are ardently for the use of this plant especially for conditions where quality of life can be significantly improved or where there are limited pharmaceutical treatments.

    Now there are medical cannabis clinics in the UK, particularly for issues such as pain and insomnia. Globally there has been a huge shift in the legislation (as well as the cultural perceptions) of this plant and it is more freely available for all sorts of conditions, as well as recreational use.

  • Research

    Sleep: Research was conducted on 147 subjects from 2 cannabis clinics in Southern California. 116 of these patients reported difficulty sleeping, and 31 reported no issues with sleep. Sleep latency (how long it takes to fall asleep) was recorded, as well as sleep quality and dreams. Subjects fell asleep significantly faster, and 79% reported increased sleep quality.

    Epilepsy: A review was conducted of 4 trials, focusing on the use of CBD (one of the main active compounds in cannabis) for Lennox–Gastaut syndrome (LGS) and Dravet syndrome (DS). Seizure frequency decreased by at least 50% for 37.2% of patients. There are various potential mechanisms of action for CBD and epilepsy, including blocking the breaking down of anandamide, targeting abnormal sodium channels and activation of transient receptor potential of vanilloid type-1 (TRPV1).

    Appetite: Two trials showed that oral THC found in cannabis can stimulate the appetite and may slow down weight loss in people with advanced cancer. It is thought that the endogenous cannabinoid system regulates feeding behaviour, for example it has been shown that anandamide (an endocannabinoid) in mice leads to increased appetite. CB1 receptors which are part of the endocannabinoid system are present in the hypothalamus where food intake is controlled.

    Pain: A trial was conducted with 176 who suffered with chronic pain, and were treatment resistant to opioids and other drugs. Factors such as pain severity, opioid consumption, and physical, social and emotional wellbeing were measured. Overall results show that there was a significant improvement in pain and functional outcomes and a significant reduction in opioid use.

  • Did you know?

    Queen Victoria was known to use cannabis for menstrual pain. Also the endocannabinoid receptor that THC (the psychoactive molecule in cannabis) is called anandamide which comes from the Sanskrit word ananda meaning bliss.

Additional information

  • Botanical description

    Cannabis is an annual, flowering herb with fine, serrated and segmented leaves that are palmately compound or digitate. Both the male and female parts of the plants flower, and the female part produces seeds.

  • Common names

    • Marijuana
    • Pot
    • Green
    • Hash
    • Grass
    • Mary jane
    • Weed
  • Safety

    There are various risks associated with cannabis, for example some people feel confused, anxious and paranoid when using cannabis.

    There are also more serious potential implications as regular users have a higher risk of developing a psychotic illness such as schizophrenia.  Risk is especially high with people who; have underlying mental health conditions such as psychosis and schizophrenia, start smoking at a young age, smoke regularly, use it for a long time, and smoke stronger types such as skunk. Additionally, if there is a family history of schizophrenia then risk is increased.

    Cannabis is still illegal to grow or use in the UK, unless prescribed by a specialist.

  • Dosage

    Dosage varies massively depending on an individual, what is being treated and method of administration. For example cannabis can be smoked, applied topically, eaten or used in a spray.

  • Constituents

    Cannabis like all plants has a plethora of compounds that work in synergy together and compounds range from cannabinoids to volatile oils, terpenes and alkaloids. This phenomena has helped many scientists shift from the perspective of having one “saviour” compound to acknowledging that complex multi-molecule extracts very often work with better efficacy and safety. Research has also shown us the individual uses of each molecule which we have summarised below. Please note that some of these studies were conducted on animals and individual compounds may not work the same in humans. Nonetheless cannabis has been used clinically for all of these different conditions.

    • CBD (cannabidiol) – anxiety, inflammation, seizures
    • THC (Δ9-tetrahydrocannabinol) – parkinson’s, psychoactive, pain, appetite
    • CBG (cannabigerol) – huntingtons, parkinsons, multiple sclerosis, IBS, antibacterial
    • Linalool – pain, anti-inflammatory
    • Myrcene – pain, anti-inflammatory, antioxidant
    • Pinene – cancer, anxiety
    • B-Caryophyllene – alzheimers, inflammation, wound healing, inflammation
An ‘aromatic’ remedy, high in volatile essential oils, was most often associated with calming and sometimes ‘warming’ the digestion. Most kitchen spices and herbs have this quality: they were used both as flavouring and to ease the digestion of sometimes challenging pre-industrial foods. Many aromatics are classed as ‘carminatives’ and are used to reduce colic, bloating and agitated digestion. They also often feature in respiratory remedies for colds, chest and other airway infections. They are also classic calming inhalants and massage oils, and are the basis of aromatherapy for their mental benefits.
Astringent taste
The puckering taste you get with many plants (the most familiar is black tea after being stewed too long, or some red wines) is produced by complex polyphenols such as tannins. Tannins are used in concentrated form (eg from oak bark) to make leather from animal skins. The process of ‘tanning’ involves the coagulation of relatively fluid proteins in living tissues into tight clotted fibres (similar to the process of boiling an egg). Tannins in effect turn exposed surfaces on the body into leather. In the case of the lining of mouth and upper digestive tract this is only temporary as new mucosa are replenished, but in the meantime can calm inflamed or irritated surfaces. In the case of open wounds tannins can be a life-saver – when strong (as in the bark of broadleaved trees) they can seal a damaged surface. One group of tannins, the reddish-brown ‘condensed tannins’ are procyanidins, which can reduce inflammation and oxidative damage.
Bitters are a very complex group of phytochemicals that stimulate the bitter receptors in the mouth. They were some of the most valuable remedies in ancient medicine. They were experienced as stimulating appetite and switching on a wide range of key digestive functions, including increasing bile clearance from the liver (as bile is a key factor in bowel health this can be translated into improving bowel functions and the microbiome). Many of these reputations are being supported by new research on the role of bitter receptors in the mouth and elsewhere round the body. Bitters were also seen as ‘cooling’ reducing the intensity of some fevers and inflammatory diseases.
Blue-purple colouring
Any fruits with a blue-purple colouring contain high levels of the polyphenols known as anthocyanins. These work 1) on the walls of small blood vessels, helping to maintain capillary structure to reduce a key stage in inflammation, and improving the microcirculation to the tissues; 2) to improve retinal function and vision; 3) to support connective tissue repair around the body.
Traditional ‘cold’ or cooling’ remedies often contain bitter phytonutrients such a iridoids (gentian), sesiquterpenes (chamomile), anthraquinones (rhubarb root), mucilages (marshmallow), some alkaloids and flavonoids. They tend to influence the digestive system, liver and kidneys. Cooling herbs do just that; they diffuse, drain and clear heat from areas of inflammation, redness and irritation. Sweet, bitter and astringent herbs tend to be cooling.
Traditional ‘hot’ or ‘heating’ remedies, often containing spice ingredients like capsaicin, the gingerols (ginger), piperine (black or long pepper), curcumin (turmeric) or the sulfurous isothiocyanates from mustard, horseradich or wasabi, generate warmth when taken. In modern times this might translate as thermogenic and circulatory stimulant effects. There is evidence of improved tissue blood flow with such remedies: this would lead to a reduction in build-up of metabolites and tissue damage. Heating remedies were used to counter the impact of cold, reducing any symptoms made worse in the cold. .
Mucilages are complex carbohydrate based plant constituents with a slimy or ‘unctuous’ feel especially when chewed or macerated in water. Their effect is due simply to their physical coating exposed surfaces. From prehistory they were most often used as wound remedies for their soothing and healing effects on damaged tissues. Nowadays they are used more for these effects on the digestive lining, from the throat to the stomach, where they can relieve irritation and inflammation such as pharyngitis and gastritis. Some of the prominent mucilaginous remedies like slippery elm, aloe vera and the seaweeds can be used as physical buffers to reduce the harm and pain caused by reflux of excess stomach acid. Mucilages are also widely used to reduce dry coughing. Here the effect seems to be by reflex through embryonic nerve connections: reduced signals from the upper digestive wall appear to translate as reduced activity of airway muscles and increased activity of airway mucus cells. Some seed mucilages, such as in psyllium seed, flaxseed (linseed) or guar bean survive digestion to provide bulking laxative effects in the bowel. These can also reduce rate of absorption of sugar and cholesterol. .
New-mown hay aroma
The familiar country odour of haymaking, of drying grass and other plants, is largely produced by coumarins (originally isolated from tonka beans – in French coumarou) and widely used in perfumery. They are chemically categorised as benzopyrone lactones and are important phytochemicals, with strong antioxidant activity in the laboratory and likely effects in modulating inflammation. They were most often associated with the calming effect linked to their use in stuffing mattresses and pillows and plants, high In coumarins were commonly used for these properties.
Resins are most familiar as tacky discharges from pine trees (and as the substance in amber, and rosin for violin bows). They were most valued however as the basis of ancient commodities like frankincense and myrrh (two of the three gifts of the Three Wise Men to the baby Jesus) and getting access to their source was one benefit to Solomon for marrying the Queen of Sheba (now Ethiopia). Resins were the original antiseptic remedies, ground and applied as powders or pastes to wounds or inflamed tissues, and were also used for mummification. With alcohol distillation it was found that they could be dissolved in 90% alcohol and in this form they remain a most powerful mouthwash and gargle, for infected sore throats and gum disease. They never attracted much early research interest because they permanently coat expensive glassware! For use in the mouth, gums and throat hey are best combined with concentrated licorice extracts to keep the resins in suspension and add extra soothing properties. It appears that they work both as local antiseptics and by stimulating white blood cell activity under the mucosal surface. They feel extremely effective!
The salty flavour is immediately distinctive. A grain dropped onto the tongue is instantly moistening and a sprinkle on food enkindles digestion. This easily recognisable flavour has its receptors right at the front of the tongue. The salty flavor creates moisture and heat, a sinking and heavy effect which is very grounding for the nervous system and encourages stability. People who are solid and reliable become known as ‘the salt of the earth'.
The sharp taste of some fruits, and almost all unripe fruits, as well as vinegar and fermented foods, is produced by weak acids (the taste is generated by H+ ions from acids stimulating the sour taste buds). Sour taste buds are hard-wired to generate immediate reflex responses elsewhere in the body. Anyone who likes the refreshing taste of lemon or other citrus in the morning will know that one reflex effect is increased saliva production. Other effects are subjective rather than confirmed by research but there is a consistent view that they include increased digestive activity and contraction of the gallbladder.
In the days when most people never tasted sugar, ‘sweetness’ was associated with the taste of basic foods: that of cooked vegetables, cereals and meat. In other words sweet was the quality of nourishment, and ‘tonic’ remedies. Describing a remedy as sweet generally led to that remedy being used in convalescence or recovery from illness. Interestingly, the plant constituents most often found in classic tonics like licorice, ginseng are plant steroids including saponins, which also have a sweet taste.

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