After taking the initial tests, the participants were given a microdose of dried psychedelic truffles, and after approximately 90 minutes—the tail end of the drug’s “peak period”—they retook all three tests. On average, the participants scored higher on the two creativity measurements, divergent and convergent thinking, after microdosing. The results for fluid intelligence, which can be roughly described as reasoning and problem solving, were about the same.

“Our results suggest that consuming a microdose of truffles allowed participants to create more out-of-the-box alternative solutions to a problem,” the authors write in the study. (The authors did not return requests for comment.)

While an intriguing study, it’s worth holding off on purchasing a baggie of magic truffles until we have clearer data. The study was posted as a preprint and has not yet been peer reviewed. And Matthew Johnson, an associate professor of psychiatry and behavioral sciences at Johns Hopkins University who has researched psychedelics, brought up some concerns about the study’s results. “I have virtually no confidence that this isn’t driven by placebo effect. The effects that they have presented are so subtle that they’re exactly what one would expect from a placebo effect to result in,” he says. “Someone might say, ‘I had one of those days where I felt more alert, in the zone, connected with people a little better, I was just in the zone.’ But we all have those types of days, and sometimes expecting to have those days, you’ll have one of those days.”

The authors address this potential placebo effect in their study, acknowledging that they can’t absolutely rule out that their results are influenced by subjects’ expectations. Johnson notes that the effects of microdosing psychedelics aren’t just unclear in this study; they’re unclear in general. “We know nothing about microdosing scientifically,” he says. “There’s lots of anecdotal evidence … [but] we don’t know anything about its effects in labs.”

Matthew Baggott, a neuroscientist who has studied psychedelics’ effects on people, also mentioned the lack of clarity regarding microdosing. “People have many beliefs about benefits from it, but there’s very little research to support any of the proposed benefits. This is partly, perhaps even mainly, because controlled studies in a laboratory have not yet been done.”

Likewise, there’s been little research on psychedelics’ effects on creativity, though a few were conducted in the 1960s, before President Richard Nixon called the psychologist Timothy Leary “the most dangerous man in America” for promoting psychedelics’ therapeutic potential, and the United States government halted most research involving psychedelics. One study, from 1966, suggests that LSD could improve subjects’ creative-problem-solving ability. Conversely, a study from 1967 found that while anxiety symptoms decreased after taking a high dose of LSD, creative thinking did not increase.