Inside the cannabis industrial complex The medicinal market is booming in Britain

Beneath bright and even lighting, the temperature never deviating by more than half a degree, rows of cannabis plants stretch far into the distance. Each is genetically identical, drip-fed with nutrients and exactly 1.5 metres high. Every stem bears clusters of small, off-white flowers. The scent of THC, tetrahydrocannabinol, hangs thickly in the purified air.

“We’re growing enough for 4,000 prescriptions a month,” says James Leavesley, CEO of Dalgety, the firm that built and owns the facility. “So far we’ve invested £12 million. But we plan to expand to meet the needs of 22,000 patients.” To get this tour, I’ve had to sign a non-disclosure agreement, which means the only thing I can say about the location is that it’s somewhere in the Midlands. Security, supplied by ex-soldiers, is tight. Should a criminal gang try to steal the crop, an armed police response is only a phone call away.

Licensed by both the Home Office and the Medicines and Healthcare Regulatory Agency (MHRA), Dalgety is one of four firms that run legal cannabis farms in Britain, and represents the most respectable end of the country’s burgeoning medicinal cannabis market. Jane Sawyers, a former Staffordshire chief constable, is a non-executive director, and until she became a minister last year, so too was the former Labour Home Secretary Jacqui Smith.

When regulations on medicinal cannabis were first eased seven years ago — following a campaign by parents desperate for an effective treatment for epilepsy in their children — this is roughly what was envisaged: a robust and regulated operation, providing rigorously tested products to people with specific clinical needs.

This, however, is not what most of Britain’s £300 million medicinal cannabis industry actually looks like. Nor is it why figures like Snoop Dogg are so keen to invest. What has emerged, rather, is an online bazaar — below the radar, but perfectly legal — in which British patients can obtain imports of ultra-high strength cannabis from American and Canadian companies whose brand names emphasise their non-medical purpose. “Fuck Around and Find Out” and “Haymaker Haze” are just two among many, the latter fronted by the ex-boxer and convicted rapist Mike Tyson. Most are not supplied in any recognisable medicinal form, such as capsules, but as cannabis flowers to be vaped or smoked.

The fact that non-medical cannabis remains illegal in Britain has not stopped doctors from prescribing these brands, marketed as lifestyle products in jurisdictions where marijuana is legal, for medicinal purposes at private clinics. Meanwhile, the Government is only starting to wake up to the risks, particularly when it comes to cannabis-related psychosis. Just last Thursday, its Advisory Council on the Misuse of Drugs announced plans to investigate whether legalisation has had its “intended impact” — and to identify any “unintended consequences”.

Certainly, evidence implying this isn’t hard to find. “This cannot be real,” writes a contributor to a Reddit forum on medicinal cannabis. “I just got my first order. I can’t believe I’m holding weed legally.” Strains UK, a dedicated cannabis review website, also lauds high-THC brands being prescribed by doctors. One example, known as “Gorilla Glue”, is apparently famous for “putting users into an amazing daze!” Another is “Lemon Cherry Gelato”, whose users find that “every hit will make you grin like a fool”.

How did we get to this point? Cannabis, after all, is still a Class B substance under the Misuse of Drugs Act, which means those caught selling or importing large quantities illicitly face hefty jail terms. In theory, possession is illegal too, though this is rarely enforced.

Yet there are also legal ways to secure cannabis. By the middle of the last decade, a handful of pharmaceutical products derived from the plant had been licensed. One example is Sativex, a mouth spray used to treat nerve damage caused by multiple sclerosis. That was shadowed by a broader campaign to legalise cannabis for medicinal use, led by MPs such as Labour’s Paul Flynn. In 2016, the All-Party Parliamentary Group for Drug Policy Reform issued a report saying the medicinal use of cannabis should be permitted, with the document co-authored by an NHS neurologist called Mike Barnes.

Spooked by the publicity given to childhood epilepsy, the then-Home Secretary Sajid Javid oversaw the legalisation of medicinal cannabis in November 2018. This meant that cannabis could be privately prescribed by doctors registered as consultant specialists with the General Medical Council (GMC). According to Professor Trevor Jones, a former government adviser who developed drugs to treat epilepsy and HIV as head of research at the Wellcome Trust, regulation was supposed to be “extremely strict”. Advertising the drug is unlawful, and prescriptions are supposed to be based on “purely therapeutic considerations”.

However, the rules do not specify what type of specialists are permitted to prescribe cannabis. The GMC says that “any doctor on the specialist register in any specialty” is permitted to do so, with perhaps 140 working across the country. Nor is there any restriction on the conditions for which cannabis can be administered. Classed as a “special category” drug under the Human Medicines Act, it can be privately prescribed for any patient whom a doctor considers has an “unmet clinical need”. This includes conditions for which it is banned in the NHS, such as pain relief, depression or anxiety, because of a lack of evidence.

“Many patients use the clinics simply to get marijuana and not be arrested,” Jones says, “and that’s not good medical practice.” All the while, prescriptions have soared. In 2020, private clinics and pharmacies dispensed just 4,000 prescriptions. Yet though new NHS prescriptions are rare — the Care Quality Commission (CQC) stated there were fewer than five across the country in 2022-3 — in the year to March 2024 the number of private prescriptions increased by 130%, to 346,000, following a jump of 119% the year before. In 2024, legal imports of the drug also more than doubled. Industry sources says there are roughly 75,000 patients nationwide.

There are now 43 cannabis clinics in the UK, including Mamedica, the outfit with which Snoop Dogg has announced his £4.5 million investment, and which alone claims some 7,500 patients. Mike Barnes, co-author of that 2016 parliamentary report, is doing well too: his consultancy firm Maple Tree has advised more than 300 private cannabis clinics, pharmacies and distributors.

Taken together, this gaggle of private clinics provide cannabis prescriptions for over 70 conditions, including not only anxiety, depression and chronic pain, but also more surprising ailments such as psoriasis. Most operate entirely online: patient and doctor will never meet face to face, but rather conduct a short video interview following a written survey. The clinics are supposed to be regulated by the CQC, but so far, it has inspected just 17 out of 43. The cost for an initial consultation is usually about £100, but after that, there is bigger money to be made, with some patients paying more than £2,000 a month for cannabis.

The consequences, says Professor Sir Robin Murray, one of the world’s pre-eminent experts on the links between cannabis and psychosis, can be disastrous for mental health. To explain what he means, he describes one of his patients at Britain’s only cannabis psychosis clinic at the Maudsley Hospital in London. His patient was a young man who had totally lost the ability to distinguish between his psychotic delusions and reality. With treatment, Murray’s patient improved — until he was prescribed medical cannabis from a private clinic. Far stronger than the illegal drugs he had smoked previously, Murray’s patient slipped back into psychosis. More than a year on, he’s still sectioned under the Mental Health Act.

There are no reliable statistics on how many medicinal cannabis patients have become psychotic. But there is good international evidence that frequent intake of high-strength cannabis increases the risk — and here the situation is especially worrying. For if the dried leaf marijuana found in Britain 40 years ago was just 3% THC, which Murray likens to a weak draught lager, private clinics now regularly prescribe cannabis 10 times as strong. Once again, that’s arguably a function of lax regulation. Remarkably, the law sets no limit on a prescription’s potency, while The Lancet has found that smoking high-THC cannabis daily increases the risk of psychosis by at least 400%.

Cannabis clinics say they will not prescribe the drug for anyone with a history of psychosis. But many who do develop psychosis after taking cannabis will never have experienced it before, with one new study finding that individuals with no history of mental health issues, and who “self-medicate” with cannabis, are actually more likely to develop problems later.

Given the potential risks, the way many clinics and suppliers market their services is a further area of concern — especially given the supposed advertising ban. On top of its investment from Snoop Dog, for instance, Mamedica operates in partnership with Cookies, a hugely popular American recreational brand founded by the rapper known as Berner, whose hits include an album called Hempire. Cookies brands available in Britain via Mamedica include the 31% THC “Hawaiian Rain”, which Strains UK says provides “an enjoyable head high and a relaxing body stone”.

Despite the advertising ban, meanwhile, Mamedica trumpeted its Cookies partnership on social media, calling it an “iconic brand”, and in June issued a promotional video presented by the comedian Dom Joly. It shows him trying unsuccessfully to buy cannabis using euphemisms such as “hippy broccoli” and “stuff”. The video never mentions the drug’s real name, but its meaning is clear. It closes with a voiceover saying: “Talk to the experts if you’re considering alternative healthcare. Mamedica — for safe, legal care you can trust.”

Then there’s Mike Tyson, whose strains, marketed under the brand name “Tyson 2.0”, and including the 28% THC Haymaker Haze, are grown in North Macedonia and distributed in Britain by PHCann International. Last year, its CEO Sasho Stefanoski said that partnering with the former boxer meant “we can lead the charge in pushing industry boundaries”.

I asked Andrew Tyler, Mamedica’s CEO, if he thought the line between using cannabis for recreational and medicinal purposes was becoming blurred, and about the risks of high THC strains. He said Mamedica ensured patients went through a “rigorous eligibility process”, with their safety the “overriding consideration”, and “where there is any personal or family history of psychosis, we do not prescribe”. Perhaps. But as even Ralph MacMurray, the man behind Medbud.wiki says, “you can’t really separate recreational and medical use”.

Of course, medicinal cannabis still retains plenty of supporters, including many seemingly conscious of the risks. One is Graham Woodward, a former psychiatric nurse who now heads the Releaf cannabis clinic. Beyond refusing to prescribe cannabis with THC of more than 25%, Releaf is also unusual in gathering data on the drug’s effects. The firm is currently working with researchers on a clinical trial for people with long Covid.

Mike Barnes, too, says he is against using strains stronger than 25% THC, and railed last year against the growth of the “pseudo-recreational market” under a medical guise. On the other hand, he is a Mamedica shareholder, whose strongest available strain comes in at 34%. He also insists that Murray overstates the risk of psychosis, arguing that with careful prescription the dangers are “minimal” — a claim that prompts Murray to suggest Barnes visit some of his patients.

Despite the new Advisory Council review, meanwhile, much of officialdom seems blind to the risks. Last year, for instance, the CQC called for a multi-agency inquiry into whether the law was working as intended. It was ignored. Jones and others recently lobbied the Home Office and the MHRA, which is supposed to grant permission for every cannabis import. He has heard nothing back, and when I asked the same departments for comment, I got no response. Jones also wrote to the GMC asking them to investigate the role of the “specialist doctors”, but was rebuffed. “The GMC,” he was told, “is not an inspectorate, and we do not proactively monitor compliance with our professional standards.”

All the while, the bonanza continues. Barnes says he thinks 2-3% of the population could “potentially benefit” from taking medicinal cannabis — altogether including about two million people. Dalgety’s James Leavesley is not quite as bullish, but points out that 1.8 million people already take illegal cannabis for medical reasons. If even half that number switched to legal prescriptions, he says, “the market would be huge”. Given the apparent risks, however, not everyone will be lighting up.

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