Rosie has just returned from the school run. She drops a bag of groceries on to her kitchen table, and reaches for a clear plastic cup, covered by a white hanky and sealed with a hairband. Inside is a grey powder; her finely ground homegrown magic mushrooms.

“I’ll take a very small dose, every three or four days,” she says, weighing out a thumbnail of powder on digital jewellery scales, purchased for their precision. “People take well over a gram recreationally. I weigh out about 0.12g and then just swallow it, like any food. It gives me an alertness, an assurance. I move from a place of anxiety to a normal state of confidence, not overconfidence.”

Over the last 12 months, I have been hearing the same story from a small but increasing number of women. At parties and even at the school gates, they have told me about a new secret weapon that is boosting their productivity at work, improving their parenting and enhancing their relationships. Not clean-eating or mindfulness but microdosing – taking doses of psychedelic drugs so tiny they are considered to be “subperceptual”. In other words, says Rosie: “You don’t feel high, just… better.”

It’s a trend that first emerged in San Francisco less than a decade ago. Unlike the hippies who flocked to the city in the 60s, these new evangelists of psychedelic drugs were not seeking oblivion. Quite the opposite. While a “full” tripping dose of LSD is about 100 micrograms, online forums began to buzz with ambitious tech workers from Silicon Valley eulogising the effect of taking 10 to 20 micrograms every few days. Others used magic mushrooms. While both drugs are illegal in the US and the UK, increasing numbers claimed that tiny amounts were making them more focused, creative and productive.

Yet the scientific evidence remains shaky. The latest study, published in February in the open- access journal Plos One and led by cognitive scientist Vince Polito, tracked the experience of 98 microdosers who were already using psychedelics – a class of drugs including LSD and psilocybin (the active ingredient in magic mushrooms).

There is, the study noted, “a perception of microdosing as a general panacea that is able to improve virtually all aspects of an individual’s life”. All 98 participants expected its benefits to be “large and wide-ranging”. Yet while some clear changes were noted – decreased mind-wandering, for example – the study found no evidence of increased creativity or life satisfaction. In fact, after six weeks of microdosing, a small increase in neuroticism was noted.

I have kids, responsibilities. I believe in what I’m doing, but having class A drugs sent in the post makes me nervous

The study’s participants did, however, report lower levels of stress and depression. It was this that drew Rosie to try it. “I’ve done the traditional treatments,” she tells me. “Therapy helped hugely – it got me out of a seriously bad place and to a functioning one. And for many years, I was functioning very well, outwardly. No one would have known. But inside, I was a mess.”

Antidepressants failed to work, so she stopped taking them after the birth of her second child, comforting herself with alcohol instead. “I wasn’t getting blind drunk and peeling myself off pavements,” she says. “But if I felt bad, my mind would immediately travel to the next drink I could have. It was the only thing that helped block out the sadness.”

That changed about a year ago, when friends began talking about microdosing. Rosie wondered whether it might have a positive effect on her mental health. She gave up booze, went online and found a company in Holland selling kits for growing your own magic mushrooms.

In the very early days, she got the dosage slightly wrong and found herself, “not tripping at all, but staring at a tree for slightly longer than passersby would find normal”. Otherwise, she says, the only down side is, “I can’t take it after 5pm or I can’t sleep.”

She is scrupulously careful to keep her mushrooms far out of the reach of her pre-teen children. “But it definitely doesn’t impair my ability to parent,” she says. “If anything, my awareness is sharpened.”

There is, however, one major danger in Rosie’s mind – its illegality. She has agreed to meet me on the proviso that I keep her identity a secret. “I have two kids. I’ve got responsibilities. And although I believe completely in what I’m doing, these are still class A drugs.” Growing kits are illegal to possess in the UK and she says: “The thought that the company now has my name and address in their records makes me nervous, as did the fact that they mailed the kit to me through the post.”

Once her kit arrived, there were more concerns. It came with strict instructions to wash her hands up to her elbows and keep her mushrooms as sterile as possible, to prevent bacteria growing. “Blue streaks appeared on their stems,” she says. “As a novice, that was really scary. I didn’t want to kill myself with contaminated mushrooms. I went on lots of forums to check, and it turned out it’s just a normal, safe form of bruising.

“It would be much safer if it was legal, so you could openly seek expert advice,” she concedes, but adds, “I’ve taken antidepressants with lists of side-effects as long as my arm. Now I’m taking something with no known side-effects and it’s working. In life, you make risk calculations every day. Is it safe to cross the road? Should I have one more glass of wine? This is just another of those. And I’m significantly happier as a consequence.”

***

Just how much of a risk is microdosing? Research in this area has a long and trippy history. Used to treat mood disorders, from anxiety to alcoholism in the 1950s and 60s, psychedelics including LSD and psilocybin became classified as illegal, class A drugs in Britain in 1971. Since the US had also criminalised them the year before, research into their clinical use ground to a halt, while horror stories about recreational overdoses and bad trips abounded.

Then, in 2011, came The Psychedelic Explorer’s Guide. Written by American psychologist and researcher James Fadiman, it introduced the term microdosing into popular culture, setting out appropriate doses (10 micrograms of LSD every three days) and including glowing first-hand reports of improved productivity. He attracted evangelical followers in the US, and then across the world. Scientific research into the practice began, too.

“There’s only one genuine concern about microdosing,” says David Nutt, former chief drugs adviser to the government and author of Drugs: Without The Hot Air. “There’s a theoretical possibility that a relatively low dose of LSD, taken every day, could narrow the heart valves.” Beyond that, he says, there is no evidence that even “full” doses of LSD are dangerous to health (though clearly, the ill-advised actions of those under its effects can be). But users should not underestimate its illegality: “Possession carries a maximum penalty of seven years in prison,” he says.

Tech workers in Silicon Valley claimed tiny amounts of magic mushrooms made them more productive. Photograph: Getty Images

Barbara J Sahakian, professor of clinical neuropsychology at the University of Cambridge’s Behavioural and Clinical Neuroscience Institute, is more cautious. She says that the “increasing lifestyle use of ‘smart drugs’ by healthy people” is not the best route to improved brain health. “Some people would prefer to take a drug, as it is rapid acting, rather than consider other means of enhancing cognition, like exercise or cognitive training, which take time and require effort,” she says. “Rather than taking short-term, inadequate solutions, such as microdosing, to long-term problems, it is time for people to consider how they can best improve their health and wellbeing.”

Yet some proponents of microdosing claim that it has enabled them to improve just that. Lindsay Jordan, 40, has just returned from a daybreak yoga class. She’s a senior university lecturer, and will soon begin planning her next lessons. But first, she takes out a small dropper bottle. She squeezes two drops of liquid on to her tongue from the pipette. It looks like Rescue Remedy. In fact, it’s 1-propionyl-lysergic acid diethylamide, or 1P-LSD, a psychedelic drug with effects almost indistinguishable from LSD. In 2016, the Psychoactive Substances Act made 1P-LSD illegal to sell or import, but not to possess. Jordan’s supply comes through a friend who bought it before the act came into effect.

She first tried LSD recreationally while in the early stages of a doctorate in education, two and a half years ago. “I came to it rather late in life,” she says. “It was as if a whole new world opened up for me. Psychedelics, combined with my doctoral study, really broadened my mind.”

She came across the work of Fadiman, and decided to experiment by taking a tenth of a full 1P-LSD dose every third day for a month. “I felt unusually alive,” she says. “Lights looked sparkly. I felt delighted. After the first month, I tweaked it so that dose days coincided with, say, visiting family. I enjoyed playing with the kids more when I was microdosing. Likewise going to weddings – I found it easier to be interested in people.”

I’ll take some on Thursday, because I’m upskilling one of my managers and it helps with my interaction and empathy

The effects may not have been dramatic, but they were wide-reaching. Jordan says that microdosing has made her significantly better at her job. “A colleague told me I’d become a lot more open, a lot warmer,” Jordan says. “My job used to be a struggle. I used to not enjoy teaching, and my students did not enjoy learning. Now I can teach in a hot stuffy room for hours and look out across a sea of smiling faces.”

Its impact was not limited to her professional life. “Microdosing contributed to the end of my marriage,” says Jordan, “because it led to me seeing what I should be doing with my life. I want to devote my energies to serving my students and my lovely friends. We both feel much freer now.”

***

The true impact of microdosing is currently being explored at Imperial College London, in the world’s first placebo-controlled study of the practice. People who have already decided to microdose are volunteering to take capsules, some of which contain their usual dose of their own drugs, others a placebo. Thus blinded, they answer questionnaires and solve online tasks designed to measure their cognitive abilities and wellbeing.

“If we do brain imaging when a full dose of psychedelics is in the brain, a lot of the functional networks that we can measure start to fuse into each other,” says Dr David Erritzoe, the study’s lead. “There’s broader communication between the networks. That could be the biology behind this ‘more-free’ state of mind or perception that people typically report.”

It could be that the same is also happening, to a lesser extent, when a microdose is taken, he explains. “Collaborators of ours in Copenhagen have recently done some interesting research, conducting brain imaging with different doses of psilocybin. It looks like the amount that the psychedelic community call a microdose actually hits quite a lot of receptors. Enough, in fact, that it could be having a valid effect.”

On the other hand: “We’re looking to see if the mean effect [of microdosing] exceeds that of the placebo effect,” says Balázs Szigeti, Erritzoe’s partner in the study. “It’s a big if. If I had to guess, I’d be torn. I’m not questioning the fact that microdosers experience a positive effect,” clarifies Szigeti. “I’m questioning whether that’s down to psychological reasons or a pharmacological effect.”

***

Chloe is 40, lives in Yorkshire and runs a business in the hospitality sector. Like Rosie, she began microdosing as a means of addressing mental health problems, after suffering “quite a serious breakdown”. Unlike her, however, she uses LSD, cutting a tab into 16 tiny triangles – a process she acknowledges is “inexact” – and taking one of these on each microdosing day.

“You can get acid delivered from the dark web, if you have a techy friend,” she says. “Otherwise you have to get it through dealers, unfortunately.” A 200mcg tab, costs her about £5, making each microdose come in at 30p. Given the irregularity with which she microdoses, she estimates that she is spending about £2 a month.

“If the impact on my life is finally finding a way out of depression, then I’m comfortable making that choice,” she says. “The first day I microdosed was the best day I’d had in five years. For so long, I’d felt like I’d been sedated. It’s so miserable when you know you used to be excitable and enthusiastic. But that day, it felt like a lightbulb had been turned on in my mind. I felt giddy, just really glad to be alive. I’d not had those feelings for so, so long.”

It hasn’t been totally straightforward; the first time her partner tried microdosing, “he had a massive panic attack. It really amplified his anxiety,” she says. “He’s done it loads since, mainly because he saw what a difference it had made to my mental health, and he has had some amazing days. But it’s not to be taken lightly, especially if you have a mental health condition. He still finds that if he’s feeling really anxious, it’s best to stay away.”

Nor does she feel microdosing helps with every task. “I’ll take some this Wednesday, because my business is expanding and I’m designing that day. Microdosing will help with the creative side. I’ll take some on Thursday, because I’m trying to upskill one of my managers and it helps with my human interaction and empathy.

“But if I knew I was going to be sitting at home doing the bookkeeping and looking at spreadsheets for hours, I wouldn’t microdose – I’d get distracted.” All the women I speak to stress that they use microdosing in conjunction with other strategies such as psychotherapy, regular exercise and a better diet.

Back in her flat, her microdose taking effect, Jordan says that the drugs shouldn’t be mistaken for a magic cure. “It’s not a linear path – it’s not as simple as, ‘Do this one thing, and everything will be fixed.’ But I’m ridiculously happy.” After I leave, she’s planning to write a seminar and catch up with some admin. “Microdosing changed my life. For me, it was a catalyst for profound and wide-reaching changes.” So much so, that she rarely feels the need to do it now. “I think that’s a good sign – it means you’re integrating what you’ve learned into your everyday life. These days, it’s a treat.”

Some names have been changed.

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