EducationThe history of medical cannabis: from ancient China to modern times

The history of medical cannabis: from ancient China to modern times

8 min read

Lucy MacKinnon

The history of medical cannabis: from ancient China to modern times


The rich history of medical cannabis can be found in some of the earth’s earliest records, where the plant appears under a variety of names (depending on the text's original language). Dating back over 4,000 years, records from ancient China to the modern day repeatedly reference the possible medical potential and associated benefits of the cannabis plant on the human body.

Ancient administraion of cannabis in medicine

It is believed that Emperor Shen Nung of China first explored the potential medical benefits of cannabis between 2696 and 2737 BC. Known as the father of Chinese medicine, Emperor Shen Nung created the Pen Ts’ao Pharmacopoeia, a medical encyclopaedia, to record the results of his experiments. This included using cannabis, or ‘ma’, to treat a range of illnesses and ailments including malaria, gout, rheumatism, and constipation.

Other historical texts suggest cannabis was being utilised medicinally in India as early as 1000 BC. The Hindu scripture Atharvaveda details five plants that are thought to relieve anxiety when consumed, one of these being Bhanga which is an edible form of cannabis. We also know that medical cannabis was administered across the Roman Empire, as it can also be seen referenced in ancient Greek and Latin documents.

19th Century to early 20th Century

Historians theorise that the practice of using cannabis medicinally had reached Britain by the Nineteenth century, following William Brooke O’Shaugnessy’s return from India. In the 1830s, the Irish Physician was working for the East India Company as an assistant surgeon, conducting experiments involving medical cannabis. In 1834 O’Shaugnessy published a report detailing the success he’d found in treating vomiting and chills in patients with cholera by using high doses of hemp tinctures.

In America, the medicinal properties of cannabis were officially recorded in the US Pharmacopoeia. Founded in 1820, the United States Pharmacopoeia (USP) publishes annual information about drugs and medicinal treatments. In the 1851 edition, ‘Extractum Cannabis’ made its debut appearance. Listed as a drug known to intoxicate and exhilarate, as well as having medicinal benefits when applied in the treatment of depression, addiction and hysteria, ‘Extractum Cannabis’ and ‘Extract of Hemp’ was removed from the USP in 1942.  This change happened following The Marihuana Tax Act, and its subsequent change in legal status.

Criminalisation of Cannabis

There were also early efforts to regulate cannabis in colonies belonging to the British Empire, including Singapore, Jamaica, South Africa and Mauritius. In 1928 the United Kingdom fulfilled their obligation as a country within the League of Nations and implemented the legislations that were decided at the International Opium Convention, criminalising cannabis usage.

In the US, The Marihuana Tax Act came into force in 1937, prohibiting the recreational use of cannabis and criminalising its sale, possession, and consumption. However, this act did allow the plant to be used for industrial purposes and the administration of medical cannabis was allowed to continue – but only if a tax was paid to the government. In 1951, strict penalties for possessing cannabis were imposed, resulting in first-time offenders being sentenced to a minimum of two years in prison and issued a $20,000 fine. 

Further restrictions on cannabis were imposed in the UK after the Misuse of Drugs Act 1971 was passed. This categorised drugs into classes or schedules depending on their level of intoxication and perceived danger. Cannabis was listed as Class B, Schedule 2 drug. 

In 2002, the Advisory Council on the Misuse of Drugs recommended that cannabis should be rescheduled as a Class C drug. This happened two years later under the Labour government led by Tony Blair but was changed again in 2009 when cannabis was reclassified back to Class B (also under the Labour government of the time, led by Gordon Brown).

Rediscovery of Medical Cannabis

Following the prohibition, criminalisation, and stigmatisation of cannabis around the world, investigations into its medical efficacy were stalled. However, during an animal study using THC, the psychoactive compound in cannabis, scientists made the first step towards understanding how cannabis is regulated biologically, by discovering the first part of the endocannabinoid system.

Researchers in the Department of Pharmacology at St Louis University Medical School in Missouri identified the first cannabinoid receptor, called CB1, in 1988. They found THC activates this receptor, causing some of the biological responses that are associated with cannabis. This caused a snowball effect in research and shortly afterwards Raphael Mechoulam’s team discovered the body was producing its own natural cannabinoids, anandamide and 2-arachidonoylglycerol (2-AG), to interact with cannabinoid receptors to regulate everyday functions.

A second type of cannabinoid receptor, CB2 was also discovered, but unlike CB1 receptors, this type was found all over the body, including in the peripheral nervous system and immune system.

Once scientists were able to understand how cannabinoids like THC and CBD behaved once in the body, investigations into how they could be administration medicinally flourished. By 1996, after years of campaigning by activists and advocates, this research was acknowledged by officials in California, which became the first US State to legally approve medical marijuana.

Known as the Compassionate Act, or Proposition 215, this 1996 act protected patients and their caregivers from prosecution if they were found to be possessing or even cultivating “medical marijuana”, so long as their physician had advised this type of treatment. Within a decade, a further ten states followed suit, and at the time of writing in 2023, medical marijuana is legal in 38 states. CBD oil is legal in another 7 states, and only 6 states have yet to legalise some form of medical cannabis.

In a momentous policy shift that took place in November 2018, the United Kingdom embarked on a groundbreaking journey by permitting the application of medical cannabis under the explicit prescription of specialist doctors. This landmark decision marked a paradigmatic change in the nation's approach to cannabis-based medicine, opening doors to new possibilities and pioneering a progressive path towards enhanced patient care. 

By embracing this transformative policy, the UK acknowledged the growing body of scientific evidence and the potential therapeutic benefits that cannabis, with its myriad of active compounds, could offer to individuals suffering from a range of debilitating conditions. The move came as a response to the collective pleas of patients, their families, and the medical community.  All of these groups recognised the potential of medical cannabis in possibly alleviating symptoms and improving the quality of life for those afflicted with conditions such as multiple sclerosis, epilepsy, chronic pain, and chemotherapy-induced nausea.

Contemporary Medical Cannabis

Research from the last decade tells us that medical cannabis has the potential to be effective in treating patients with neurological, psychological or physiological conditions. Increasing numbers of studies investigating pain management, inflammatory responses, and sleep disorders have reported successful results in regard to cannabis-based treatments.

Across the world, patients with MS, PTSD, ADHD, chronic pain, epilepsy, and Parkinson's Disease, as well as many others, are reportedly using medical cannabis to help manage their conditions. As reported in Michael H. Moskowitz’s book, THC is known to have “anti-oxidising, and antiemetic effects” and CBD is thought to have anti-inflammatory, antibacterial and analgesic qualities.

As well as having a multitude of potential benefits, medical cannabis products can come in various forms, which gives patients plenty of options when starting their journey with medical cannabis. The effects of cannabis are felt most rapidly when it is vaporised, either in flower or oil form, but some patients prefer to administer cannabis using tinctures, tablets, or balms. Cannabis-based food or drinks are also becoming a popular choice amongst medical cannabis patients.

Challenges and Controversies

Although the cannabis plant has been administered medicinally for millennia, due to its demonisation and subsequent prohibition, there is still a heavy stigma that surrounds medical cannabis. This can make it hard for researchers or clinics to find funding and accreditation for studies into its efficacy, and it can also dissuade patients from considering medical cannabis treatments in the first place.

During the 2023 Cannabis Europa event, there was an overwhelming appeal from international experts for further credible randomised controlled trials (RCTs) investigating the medicinal benefits of medical cannabis. Many noted the success and substantial amount of real-world data (along with anecdotal data) available. It was also mentioned that with a lack of data from large, credible RCTs, the British government would resist making medical cannabis treatments widely available on the NHS and are unlikely to reconsider its scheduling as a Class B drug.

Releaf understands the importance of medical cannabis in treating various medical conditions. With our tailored monthly packages, specialist consultations for medical cannabis, and a unique medical cannabis card for protection, you can access the treatment you need without worrying about the stigma. 

Further Reading:

Why was cannabis banned in the UK?

The fascinating history of hemp prohibition

A historical overview of cannabis legality in the UK

It is important to seek medical advice before starting any new treatments. The patient advisors at Releaf are available to provide expert advice and support. Alternatively, click here to book a consultation with one of our specialist doctors.

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With five years of journalism and healthcare content creation under her belt, Lucy strives to improve medical cannabis awareness and access in the UK by producing high quality, credible content.

Our articles are written by experts and reviewed by medical professionals or compliance specialists. Adhering to stringent sourcing guidelines, we reference peer-reviewed studies and scholarly research. View our editorial policy.

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