I’m sitting on a bus eating a vegan marshmallow cookie and trying to work out whether I feel more chill than usual. I’ve just visited the London outpost of plant-based restaurant chain By Chloe, and the roads back to the office are clogged with mid-morning traffic. The bus edges slowly along The Strand, but I don’t feel irritated. Could that be a sign? I take another bite and chew thoughtfully. We stop at a set of lights and I decide that I do feel mellow, also a bit nauseous because of the amount of sugar in this thing, but definitely mellow. I eat the last of the cookie. Yes, I am more chill than usual! But then a usual weekday morning for me is sitting in an office, not bunking off to eat cookies, so maybe this isn’t a fair test.

Launched last month at By Chloe’s London restaurants after a successful run in New York, the Feelz range includes a chocolate brownie, the “Rice Krispie Pinkie Treat,” a “Chocolatey Nerdy Cake” covered in rainbow Nerds, and a cupcake topped with a fondant marijuana leaf. Each of the baked goods contains 2.5 milligrams of CBD oil, mostly added to the frosting or glaze finishes to avoid heating that could cause the substance to dilate. Promotional photos released ahead of the Feelz launch show a model in 70s-style clothing reclining on a fluffy lime green rug with her eyes half-closed. She certainly looks more relaxed than I did after I getting off the bus with a half-eaten box of cookies.

“We launched Feelz By Chloe with the goal to offer a fun and delicious way for people to experiment with CBD and experience it’s benefits,” she tells me over email after I visit By Chloe’s Covent Garden location to try the new range. “The response has been really positive.”

The cookie, or to use its full title, the “A-TO-CBDEY Cookey,” is part of a new range of cannabidiol-infused baked goods from By Chloe. Cannabidiol, or CBD, is a non-psychoactive derivative of the cannabis plant. Extracted as an oil, it is legal to sell in the UK, so long as its THC content—the bit of the cannabis plant that gets you high—is less than 0.2 percent and cannot be easily extracted . While studies into CBD oil’s effect on the body are not conclusive, it is thought to have medicinal properties, including anxiety relief.

While the CBD oil used by patients such as Caldwell has a higher concentrate of THC than the stuff on sale in Holland and Barrett, the media attention surrounding cases like his have pushed non-psychoactive cannabinoids into the spotlight.

Britain’s newfound obsession with CBD food products is inspired by similar trends in Canada and the US, where growing cannabis legalisation from state to state has led to a booming new industry in weed-derived substances. Political shifts closer to home have also had an impact. In July, Home Secretary Sajid Javid announced that doctors would be able to prescribe cannabis-derived medicine, after England’s chief medical officer concluded that there was therapeutic benefit for some conditions. The announcement followed a number of high profile cases in which severely epileptic children were denied CBD oil that appeared to control their seizures, including 12-year-old Billy Caldwell, who had his medicinal cannabis oil seized at Heathrow Airport .

“There have been studies looking at CBD being used as an antipsychotic drug,” he says. “So, there have been two fairly positive-looking ones: one giving people CBD instead of an antipsychotic drug which showed improvement in symptoms but without the side effects of antipsychotics. There was another that prescribed it alongside an antipsychotic, and that showed some better reduction symptoms instead of just antipsychotic, but it needs to be done in bigger studies and clinical trials.”

Dominic Oliver, a PhD student at Kings College London, is conducting a study on the optimal balance of THC and CBD for treating psychotic disorders. He isn’t quite as cutting as Nosowitz about the effect of over-the-counter CBD oils, but does stress the need for more research.

CBD oil may be the hot new product to drizzle over avocado toast , but we don’t really know that much about what it does yet. While clinical trials show that the substance can relieve anxiety and reduce psychotic episodes, more long term studies are needed, particularly involving lower doses of CBD oil. In an article on the CBD trend published earlier this month, Vox writer Dan Nosowitz was more than a little skeptical. “Anyone who tells you anything definitive about what CBD does to you're body is lying,” he wrote.

“Sajid Javid's change in government policy has put the medicalisation process on the agenda,” says Yewande Okuleye, research associate at the University of Leicester and author of a paper on the emergence of cannabis as a medicine in Britain. “Health care professionals, policymakers, and regulators are looking for optimum ways for patients to gain access to medicinal cannabis within the NHS framework. Therefore, we now have to look at CBD as a different proposition.”

“Nice Paper helped us to educate our staff, chefs, and customers on all things CBD,” she says. “They helped us curate the CBD brands we chose to work with and sell in the By Chloe bakery in NYC, and are our go-to experts to answer any questions about CBD dosage, usage, benefits, and more.”

By Chloe’s baked goods definitely fall into novelty space cake territory—they even do a CBD-infused “peanut butter bone” for dogs. When I ask about the CBD oil research By Chloe consulted before creating the desserts, Wasser points to the restaurant’s partnership with Nice Paper , a digital publication that promotes the benefits of cannabis.

Without conclusive scientific evidence on the effects of the cannabinoid, CBD food products are marketed in wildly different ways. Some look as if they belong on the shelves of bougie health food stores , claiming to help remedy everything from pain relief to insomnia and bad days at work. Others are more like novelty space cakes .

And when it comes to the impact of CBD oil ingested with food, the research is similarly lacking. Oliver mentions a study which found that participants who took CBD with a high-fat meal absorbed as much as five times more of the substance than those who had not eaten. “One of the things about CBD is that it’s fat-soluble, so there was a recent study where they gave people CBD after making them fast for ten hours, then gave them a high-fat breakfast and a glass of full fat milk. That increased the amount of CBD that the people absorbed,” he explains. However more clinical trials are needed to fully understand how the body responds to CBD oil-infused food and drink.

He goes on to clarify the effect ingesting CBD and coffee would have on the body: “In terms of caffeine [and CBD], I don’t there’s too much research. What caffeine does when you drink it is that it increases your general metabolism, so I’d imagine that having it with coffee would mean that your body would break down the CBD faster than if you were having it without the caffeine, so probably less likely to have an effect on you having with a coffee than without.”

Oliver laughs when I tell him about the coffee jitters thing. “OK,” he says. “I haven’t heard that one before.”

“A friend of mine is in the industry [the cannabis industry in California], so we thought it would be a nice thing for Minor Figures,” Forsyth says. “In terms of what we do with innovation and quality, it seemed to tick all those boxes quite nicely—particularly the innovation side, being so new and different.”

Minor Figures co-founder Stuart Forsyth, who describes himself as “an old pothead” was also interested in the combination of CBD and caffeine as a potential aid for coffee jitters. Some studies have shown that CBD oil can up the body’s levels of adenosine , the neurotransmitter that determines our need for sleep and is disrupted by caffeine intake.

“I read an article about CBD oil and ordered some and I tried it with our coffee,” she tells me. “It was a no-brainer, really.”

East London-based coffee roastery Minor Figures is another food producer experimenting with CBD oil. Last month, the company launched a CBD tincture, designed to be dropped onto the tongue after drinking coffee “as the yin to coffee’s yang, helping to bring back balance, relaxation, and focus.” People and partnerships manager Lexie Forrester introduced some of her colleagues to CBD oil as a possible new venture after experimenting with the substance at home.

He adds: “Because we’re not allowed to have any THC content in the products here, it means people grow hemp instead of actual cannabis plants, so you get much lower levels and it’s not as strong in terms of the cannabinoids.”

“The kind of doses that we’re looking at in terms of these patient studies is 1,000 milligrams a day, so 5 milligrams is unlikely to do that much,” says Oliver. “The problem with CBD is that it’s not very easily absorbed into the body, so you only get about 6 percent of what you're actually taking. Six percent of 5 milligrams isn’t too much.”

“The problem with CBD is that it’s not very easily absorbed into the body, so you only get about 6 percent of what you're actually taking."

But when you look at the amount of actual CBD oil in products like By Chloe’s baked goods and the Minor Figures tincture, it’s not surprising that these products are marketed as “fun things.” Neither the Medicines and Healthcare products Regulatory Agency (MHRA) nor FDA have recommended dosage guidelines for CBD, but cannabis education resource CBD Origin recommends up to 6 milligrams for every 10 pounds of body weight . A By Chloe CBD-infused Rice Krispie square only contains approximately 2.5 milligrams of CBD. The maximum 15-drop dose of Minor Figures’ tincture contains just 18.75 milligrams.

Forsyth continues: “It’s a fun product. It’s really a novelty product and it’s a fun thing and it’s a bit of a stocking stuffer for cafes to get it in around Christmas.”

To be fair, Forsyth does see Minor Figures’ new tincture as more of a gimmick than a health product. Like Wasser, he didn’t consult scientific research on the medicinal qualities of CBD oil before launching it. “To be perfectly honest, I didn’t look into it all that much,” he says.

This doesn’t seem to be an issue for Minor Figures. The new tincture comes in 10-milliliter bottles containing coconut oil and 250 milligrams of CBD—which amounts to around 200 drops. (The dosage they recommend is between five and 15.) Forsyth says they aim to sell the product to coffee shops who want to “upsell the customer by 20p and put a couple of drops in,” as well as consumers making their own CBD-infused drinks or looking for a post-coffee relaxant. The bottles cost £20.

Another issue with CBD oil-infused food and drink products is that the law doesn’t technically allow you to purport any medical benefits. The MHRA states that if CBD oil is being advertised for medicinal purposes, it must have a license. However the Government has not yet granted licenses for CBD oil.

Of course, this hasn’t stopped food brands and restaurants from suggesting the many ways in which CBD oil may improve wellbeing. Rose Mann of West London cafe Farm Girl recently introduced a CBD oil-infused hot chocolate to her menu, after finding that the substance provided relief from her own anxiety. The “Happy Hot Choc” is a mix of cacao powder, mint, matcha, date syrup, hazelnut milk, and CBD oil and according to press reports at the time of its launch, aimed to “raise awareness for mental health.”

“We make a big effort not to preach to people. I would never say, ‘This cures anxiety,’ because who am I to stay that?"

When I speak to Mann, she says that she does not make claims that the CBD oil-infused beverage can do the same for others.

“We make a big effort not to preach to people,” she explains. “I would never say, ‘This cures anxiety,’ because who am I to stay that? I’m not a nutritionist, so I make sure I’m really careful with that but at the same time, I know that CBD has helped me. It might also been other factors that have helped my anxiety as well, but I genuinely think it has.”

High Tide, a CBD oil-infused cold brew coffee launched in Bournemouth last month, has a similar origin story. Co-founder Josh Kay began spiking his cold brew with drops of CBD oil after he found the substance to help with stress relief.

“I found out about CBD through Holland and Barrett,” he tells me. “I looked into it and was interested in the benefits of it. I’ve never been a recreational smoker or anything myself, so I thought, ‘I’m gonna try this,’ and I grabbed some from there. It has really helped me with stress and anxiety, work-wise. Once I’d started using the CBD, it helped clear my head, helped me focus, and helped me relax in the evening.”

Like By Chloe’s brownies and the Minor Figures post-coffee drops, High Tide bottles contain minimal amounts of CBD. However Kay says that the product is selling well, particularly in health food shops.

“If someone is going to buy a coffee, they’re not necessarily going to understand about CBD and how it allows you to use caffeine to its full extent. But someone who goes into a health food store, they’re really open to it and want to try it.”