In the most recent season of Clarkson’s Farm, the Amazon Prime show that follows Jeremy Clarkson as he tends his Cotswolds farm in the UK, the eponymous gearhead-turned-agronomist finds a lucrative sideline growing fungi in a converted bunker.

But his mushrooms aren’t just destined for risotto: They’re dried and powdered to be added to your morning cup of joe, resulting in so-called mushroom coffee—once the confine of hippies and biohackers, but now evidently as mainstream as it gets.

Startup bros, alt-health gurus, and baristas have been trying to reinvent coffee for years. We’ve had bulletproof coffee, turmeric lattes, CBD coffee, and now the mushroom variety. A slew of startups are trying to push this latter trend further, packing more and more supposedly beneficial ingredients into a single cup.

Their products are often marketed as “functional” or “adaptogenic”—adaptogens being substances purported to help modulate stress. They boast claims of improving focus, promoting calm, and enhancing creativity. Essentially: They promise more from your coffee than just a caffeine buzz.

People are clearly intrigued. Google Trends shows interest in “mushroom coffee” climbing steeply since summer 2022, and the overall functional drinks market—which also includes things like conventional energy drinks and protein drinks—is predicted to reach $307 billion by 2029. But can these new mushroom-enhanced drinks really take the place of your go-to caffeinated brew? Do their claims stand up beyond the Instagram ad hype? Most importantly, do they taste like mushroom soup?

California-based Four Sigmatic is an early innovator in the space, having been founded in 2012. Founder and CEO Tero Isokauppila credits his upbringing on a Finnish farm for his interest in adaptogens: Finns, he says, are “very pro-mushroom.” The country also has a history of mushroom-based drinks; in the Second World War, coffee rationing led people to make a tea out of steeped chaga mushrooms.

Four Sigmatic’s most popular “Think” blend is a fairly straightforward take on mushroom coffee, mixing a dark roast coffee with extracts of lion’s mane and chaga mushrooms. When I brewed a pot, it looked and smelled just like regular coffee. It tasted like it, too—on the bitter side for my liking, but with a merciful lack of any mushroom flavor.

More Wired, Less Caffeine

The idea, Isokauppila says, is to enhance the benefits people already enjoy from coffee. Four Sigmatic aims to increase focus and energy without the need to keep consuming more caffeine, which some people complain upsets their digestion or causes jitters. “That was the founding vision: That you need less caffeine while getting all this goodness in you,” he says.

After drinking Four Sigmatic’s mushroom coffee for a few days, I didn’t feel the huge boost in focus and energy about which some reviewers wax lyrical, but I was content enough to swap out my regular black coffee. While some people notice effects from the first cup, Isokauppila says, most enjoy benefits after seven days.

Adaptogenic substances have been used in many cultures for a long time, but recent Western studies are limited, and the quality of evidence varies. Lion’s mane is one of the best-studied among common mushroom coffee ingredients, with some research suggesting positive effects on cognition and stress.

Frédéric Meunier, a professor of molecular neuroscience at the Queensland Brain Institute in Australia, recently led a study (in mice) on the impact of lion’s mane on memory. He says he was happily surprised both at the results and the level of public interest—but this doesn’t necessarily mean that mushroom-enhanced beverages on the market will have the same effects.

Firstly, it’s hard to know exactly what you’re getting. Like other supplements, functional drinks are regulated as food and aren’t subject to the more rigorous testing and regulation of medicines. “You’ve got a lot of cowboys out there,” Meunier says. A 2017 study looking at reishi mushroom supplements found that only a quarter of products tested actually contained the ingredient measurements stated on the label.

How companies extract and prepare the adaptogenic compounds may also impact their efficacy, and there’s little consensus on what might be the most effective dosage for these ingredients—not that this stops many drinks brands from boasting about their milligrams per serving.

Placebo Effect

Even with the right ingredients, the kinds of claims made by most functional drink brands are very hard to test. Benefits like improved focus or calmness are largely subjective, and positive outcomes could also be the result of the placebo effect: If you’re buying these products, you likely expect a certain outcome, which can be a self-fulfilling prophecy.

Tim Spector, a professor of genetic epidemiology and cofounder of science and nutrition company ZOE, says that any effects are likely to be subtle and not noticeable for everyone. “It’s also worth considering that the ritual of preparing and consuming these beverages, along with the caffeine or other stimulants they may contain, could contribute to the perceived benefits,” he says.

While Four Sigmatic smuggles its adaptogens directly into coffee grounds, many adaptogenic drinks pitch themselves as something alternative, often with a lower caffeine content. UK-based Spacegoods’ Rainbow Dust, unmissable in bright pink and purple packaging, contains 80 milligrams—less than most coffees. Its ingredients list boasts lion’s mane, cordyceps, and chaga mushrooms, alongside other plant-based adaptogens ashwagandha, maca root, and rhodiola rosea. It’s a lot to pack into a spoon of powder, which comes in flavor options of chocolate, coffee, strawberry, vanilla cinnamon, and a decaffeinated raw cocoa variety.

Ecommerce entrepreneur Matthew Kelly launched the brand in 2022 following the failure of his previous business, an online neon sign retailer that went into administration in 2021. Kelly came across functional mushrooms while scrambling to figure out his next move.

Kelly’s ecommerce background is clear in Spacegoods’ online presence. Like many of the direct-to-consumer functional drink brands, the company heavily promotes a subscription model, and after purchasing some Rainbow Dust I found myself chased by Instagram ads and marketing emails promising all sorts of benefits.

Kelly admits that advertising adaptogenic drinks requires treading a delicate line. Manufacturers want to shout about their products’ potential benefits, but the UK’s Advertising Standards Authority forbids claims that food products could prevent, treat or cure human disease; various brands have had to pull ads that mention health conditions such as anxiety, dementia, or ADHD.

I tried the original chocolate flavor of Rainbow Dust and found it to be sickly sweet. Granted, it didn’t taste like mushrooms, but it didn’t exactly put me in mind of a health drink. Kelly concedes that pitching a chocolate-flavored drink as an improvement on coffee may have confused some buyers; he prefers the coffee flavor, introduced this year.

Those with a more grown-up palate may wish to try US brand MUDWTR—a name founder Shane Heath says was inspired by his colleagues’ reactions to his homemade prototypes and which ended up having “natural virality.” A former caffeine junkie, Heath turned to coffee alternatives after noticing negative effects on his sleep and mood. His tagline: “I wasn’t mad at coffee, just disappointed.”

Whisk Assessment

The original version of MUDWTR contains only 35 milligrams of caffeine, alongside lion’s mane, cordyceps, chaga, and reishi mushrooms, as well as a few other ingredients. Its real winning formula, however, is in its cacao and masala chai flavoring. The natural earthiness of the spices cleverly masks any unpleasant mushroom taste. Made by mixing with either hot water or milk, it’s not anything like coffee but still feels sophisticated (although I did find quite a lot of sediment settled to the bottom of the cup).

I initially scoffed at the company’s insistence on selling its powder in a starter kit containing a mini electric frother, but as I whisked up a cup, I recalled Spector’s observation about the role of ritual in amplifying perceived benefits and wondered if this additional preparation step was in fact a shrewd decision. It forced a pause which in itself inspired focus—Right, I’m going to whisk up this drink and then sit down to write that story. I’m pretty sure my ensuing productive writing session was largely a result of the placebo effect, but I’ll take it.

It’s an attitude echoed in some online reviews for mushroom coffee. Sure, it may be impossible to tell if they’re actually doing anything—but if you feel like you’re getting some benefit, and you like a hot drink anyway, what’s the difference?

In the early days of his business, Neil Marrakchi, cofounder of mushroom coffee brand Reformed, says he used to call each new customer three days after delivery. Some were rapturous about the product, which also includes collagen as its star ingredient, saying it had changed their life. “But to be totally transparent with you, I think this is very psychological as well,” he says.

All of the companies I spoke to said their consumers were split fairly evenly across gender lines and varied in age. As well as the productivity maxxers and fitness fans, several said their drinks had found particular appeal among new parents.

As companies jostle for position, there’s a pressure to keep innovating. “Our food-science team is constantly playing around with novel ingredients and juxtaposing them against the regulatory landscape,” says Heath of MUDWTR. He highlights proteins and nootropics—substances thought to enhance cognitive function—as areas of future interest. Other brands are emerging that pitch chilled, ready-to-drink beverages with adaptogenic ingredients as alternatives to cocktails for the sober-curious, such as Katy Perry-cofounded De Soi, or as a new take on energy drinks, such as Gym Weed (cocreated by the company behind protein brand Muscle Milk).

Some companies are bound to fall by the wayside as the space develops, but Jordan Rosenacker, cofounder of coffee subscription service Atlas Coffee Club—which is planning its own coffee alternatives launch later this year—reckons the overall idea will persist beyond a fad. He ties the interest in adaptogens to broader health trends since the turn of the millennium, including increased interest in mindfulness and mental well-being as well as physical fitness, supercharged by social sharing. A confirmed coffee lover, even he craves something different later in the day. “At some point I need to sleep, you know,” he says.