Some people who use psychedelic drugs such as LSD or magic mushrooms are routinely taking “microdoses” of the drugs, LiveScience reports.

The trend has gained a cult following among a small group of people, who say the tiny doses improve their perception, mood and focus, without the hallucinogenic effects of larger doses.

Martijn Schirp, who writes for HighExistence.com, says small doses are “like the coffee to wake up the mind-body connection. When I notice it is working, depending on the dosage, time seems to be slowing down a bit, everything seems covered with a layer of extra significance.”

Matt Johnson, a psychologist at Johns Hopkins University in Baltimore, who has studied the behavioral effects of psychedelic drugs, says there is no scientific evidence about the effects of microdosing. He notes that while taking a smaller dose of a psychedelic drug is safer than taking a larger dose, there could be long-term side effects from regularly taking small doses every several days.

Johnson told LiveScience that psychedelic drugs activate a receptor in the brain that fuels the release of serotonin, the “feel-good” brain chemical. He said it is possible people using microdoses of psychedelic drugs are experiencing the placebo effect, in which people taking a dummy pill believe they are taking a real drug, and report perceptible effects.

Johnson noted that because LSD is an illegal drug bought on the black market, there is no way for a person to know exactly what they are getting. In addition, he notes there is substantial variation in how people react to psychedelic drugs.

“Someone might be expecting a kind of sparkly day, just a really productive day at work — and next thing you know, they’re grasping hold to their office chair wondering why the world is dissolving,” he said.