You’ve probably heard about microdosing, the “productivity hack” popular among Silicon Valley engineers and business leaders. Microdosers take regular small doses of LSD or magic mushrooms. At these doses, they don’t experience mind-bending, hallucinatory trips, but they say they get a jolt in creativity and focus that can elevate work performance, help relationships, and generally improve a stressful and demanding daily life. If its proponents are to be believed, microdosing offers the cure for an era dominated by digital distractions and existential anxiety—a cup of coffee with a little Tony Robbins stirred in.

So far, though, it’s been impossible to separate truth from hype. That’s because, until recently, microdoses haven’t been tested in placebo-controlled trials. Late last year, the first placebo-controlled microdose trial was published. The study concluded that microdoses of LSD appreciably altered subjects’ sense of time, allowing them to more accurately reproduce lapsed spans of time. While it doesn’t prove that microdoses act as a novel cognitive enhancer, the study starts to piece together a compelling story on how LSD alters the brain’s perceptive and cognitive systems in a way that could lead to more creativity and focus.

The idea behind microdosing traces its roots back decades. In the 1950s, a handful of psychedelic therapists at a mental health facility in Saskatchewan wanted to help alcoholics get clean. They guided the patients through a high-dose, ego-dissolving, LSD experience. When they came out the other side, over half of the patients reported complete recovery from alcoholism. The Canadian government was intrigued and ordered more rigorous trials, this time with placebo controls, and without the experienced “trip guides” offering suggestions on what patients should feel. These trials were a bust. In the fallout, many viewed psychedelic therapy as more shamanism than science. The mindset of the user and suggestion from the therapist (termed “set and setting” to LSD proponents) are just as important as the drug itself. In other words, LSD’s effects had as much to do with goings on outside the brain as inside it. To LSD proponents, though, this was part of how it worked. “Set and setting” guard against a bad trip (with large doses), and give the user an idea of what they should experience.

Microdosing is born from this “set and setting” school of psychedelic therapy and one of its intellectual progeny, James Fadiman. The Stanford-trained Fadiman has worked with psychedelics for decades and runs a kind of cottage industry around espousing their powers. In his 2011 book The Psychedelic Explorer’s Guide and at a conference talk that same year, Fadiman laid out the concept of microdosing. To microdose, one was to take a dose roughly 1/10th of a trip-inducing dose (10 micrograms of LSD) every three or four days, and go about their daily life.

Most of what’s known about the benefits of microdosing comes from self-reports Fadiman collected (and continues to collect) where microdosers described how the practice transformed their lives. In them, microdosers speak of anxiety and depression melting away, and feelings of determination and self-resolve that helped them achieve professional success. Some color-blind men even saw color for the first time.

The self-reporting experiment doesn’t involve placebos or self-blinding, where participants hide dosage information from themselves, and thus is extremely susceptible to observer-expectancy bias. For his part, Fadiman admits that what he does is more “search” than research. But, it’s quite clear that a prospective microdoser gets expectancy bias (or the right “set and setting” depending on who you ask) from online journalism, Reddit (r/microdosing has close to 50,000 subscribers), or even a consultant. This makes the phenomenon of microdosing more similar to the fringy 1950s Saskatchewan studies than the serious-minded psychedelic research that’s sprung up parallel to it.

The phenomenon has gotten so much attention, though, and the claims are so intriguing, that some scientists are attempting to test them with some rigor. A group of psychologists at Goldsmiths, University of London, led by Devin Terhune, published the first placebo-controlled study on microdosing in late 2018. Terhune recruited volunteers who hadn’t used LSD in the preceding five years and randomly assigned them into placebo or LSD microdose groups.

Terhune first addressed a simple, but actually elusive, question: are you supposed to feel a microdose of LSD? Many online resources describe microdoses as “subperceptual.” In other words, no, you’re not supposed to feel the drug take effect. This makes LSD microdoses closer to an antidepressant like Prozac than a truly psychoactive substance like caffeine or marijuana. Others argue that, no, you should feel the microdose, and if you don’t, it’s not working. As part of a questionnaire, subjects were asked the simple question, “Do you feel the drug?” Interestingly, Terhune found no statistical difference in responses to that question between the placebo and LSD groups. Though this study was limited in scale, it argues that, no, you’re not actually feeling anything when you microdose.

But does a microdose change brain function in a subperceptual way? There’s a myriad of ways to test this, but Terhune looked specifically at the way the subjects perceive time. When shown a blue dot on a screen for a specific length of time, the subjects were asked to recreate that length of time by pressing a key. Typically, with longer time intervals, people underrepresent time (i.e. hold the key down for a shorter period of time than reality). In the study, those who received microdoses held the key longer, better representing the actual time interval.

Does this mean microdosing makes you smarter? Terhune and his co-authors were cautious in overinterpreting their finding. For one, it’s not clear that perceiving time more accurately is preferable. The brain seems to favor underrepresenting time for reasons that are unclear. Disrupting the brain’s default way of representing time, though, may beneficial in certain daily tasks or creative pursuits. That’s not clear yet, and the relationship between time perception and cognitive function needs to be further developed. Importantly, though, the finding does show that microdoses changed brain function in some way, despite not inducing a strong drug “feeling.”

As Terhune and others start testing the meatier microdosing claims with rigorous methods, the era of psychedelic research that James Fadiman had a hand in creating is closing. Organizations that fund psychedelic research are showing more interest in testing microdoses alongside placebo controls. One study, according to its website, will test “the short-term effects of various sizes of LSD microdose on creativity, cognitive flexibility and well-being” and “brain activity, cognitive functions and mood” over a four-week period.

So what’s riding on these studies? For those who are already convinced of microdosing’s powers, probably not much. But quite a lot is at stake for our broader understanding of the brain and the potential for drugs—LSD or otherwise—to enhance cognitive abilities. Unlike large doses of psychedelics, microdoses don’t dissolve your ego. You don’t become a better version of yourself by falling apart and coming back together, like the Saskatchewan alcoholics. Instead, the mythology around microdosing tells a different, and perhaps even more compelling, story. Through straightforward pharmacology, microdoses may activate just the right amount of receptors for us to be our better selves.