Benefits From Microdosing Psychedelics May Be a Placebo, Says Study

It found no significant difference in the psychological wellbeing of participants who took LSD or psilocybin mushrooms, and those who took a placebo capsule. 
Shamani Joshi
Mumbai, IN
microdosing placebo study
A microdose used in the study by Szigeti et al. Photo courtesy of Self-blinding microdose study team (CC BY 4.0)

Microdosing, which refers to taking tiny amounts of psychedelics like LSD, has emerged as one of the biggest wellness trends over the last decade. Despite psychedelics being banned in most countries, people have microdosed in an attempt to unlock their creative potential, win more rounds of the Chinese game of Go, or even overcome long-held mental trauma. Most psychedelic advocates have sworn by the feel-good effects of microdosing — which they say allows the user to feel happy and productive without the harrowing hallucinations and daunting delusions of “tripping balls”. But, there hasn’t been enough clinical research to support this theory. Now, microdosers will not be pleased to know that a study has found that the psychological benefits of microdosing psychedelics are probably just a placebo effect


In the largest placebo-controlled trial with psychedelics ever held, researchers from Imperial College London asked 191 participants who were already microdosing to disguise a microdose of LSD, psilocybin mushrooms or other psychedelics — usually about a tenth of the “trip” dose of a drug — in capsules, and then mix those with empty placebo capsules in a self-blinding method.

The trial, which was launched in 2018, wasn’t conducted in the confines of a laboratory, nor were the drugs provided by the researchers. Instead, volunteers were asked to put their microdoses into opaque pill capsules, and send a week’s worth of these capsules to the lab in an envelope which had a QR code. The researchers then mixed these microdose pills with others that contained placebos, so that some participants would only take microdoses for four weeks, some would only take the placebos, and some would get a mix of both. Researchers had scanned the QR codes on these envelopes to determine which pills were which. Participants were then asked to complete cognitive tasks and online surveys at regular intervals, to understand the effects the capsules were having on their psychological well-being and cognitive functioning. This method also made the study more cost-effective, allowing researchers to complete the study for less than $10,000. 

After the month-long trial, researchers found that those who had microdosed showed a boost in their psychological mood, including improved feelings of well-being, mindfulness, life satisfaction, and reduced paranoia. But the surprising part of this was that the placebo group also displayed similar psychological effects, with no significant differences between the two.


“Microdosing did increase a lot of these psychological variables. But so did taking placebos for four weeks,” said Balázs Szigeti, a research associate at Imperial College London Centre of Psychedelic Research and the lead author of the study. "Many participants who reported that they experienced positive effects while taking the placebo were shocked to learn after the study that they hadn't been taking the real drug."

This, the researchers concluded, points to the likelihood that the anecdotal feel-good benefits of microdosing psychedelics may be a placebo effect. Szigeti also clarified that this doesn’t mean microdosing psychedelics didn’t have benefits, but that its effects on our wellbeing are probably more an outcome of the psychological expectation than any pharmacological effects. 

“I have just checked the remaining envelopes and it appears that I was indeed taking placebos throughout the trial. I'm quite astonished,” said one participant quoted in the study. Another added, “It seems I was able to generate a powerful 'altered consciousness' experience based only the expectation around the possibility of a microdose.” Some participants who took the placebo reported that  “colours were more vivid”, while they were able to stay focused on the test and feel new sensations. One said, “You put spirituality into an empty pill here...wow!”

Both the microdosing group and the placebo group showed an overall improvement in their psychological well-being compared to a baseline taken at the start of the study. However, both the groups of participants did not show any significant improvement in their cognitive measures, which are also less subjective in nature. “So people are cognitively performing at the same level before and after these four weeks long dose period,” Szigeti noted.


While the scientists stand by their conclusions, they have also accepted the criticism that the study is not as foolproof as a standard, laboratory-based placebo-controlled clinical study, since the participants sourced their own drugs from the black market and took them in their homes. However, the research team countered that by stating that this approach accurately reflects “real-life microdosing”. Critics of the study also pointed out that this made it impossible to be sure what doses each participant had taken, especially since many of them would be likely to understand the effects of the drug enough to guess whether they’d taken a microdose of psychedelics or a placebo capsule.

The study researchers also made it clear out that this study was more observational than clinical, and proposed that it could be used as a screening tool before engaging in more expensive clinical trials. “This is a citizen science study that has an interesting twist that adds placebo control,” said Szigeti. 

Szigeti also admitted that the study probably wouldn’t change much for the microdosing community. “I think most microdosers don't care that much whether it's a pharmacological or placebo effect,” he said.“They’re just going to enjoy the effects that they get.”

However, scientists remain positive that this study is a stepping stone to understanding more about the effects of psychotropic substances on the human psyche. "The successful execution of this study could inspire similar studies in a broad range of scientific or medical contexts," says senior author David Erritzoe, clinical senior lecturer in psychiatry at Imperial College London. “Accounting for the placebo effect is important when assessing trends such as the use of cannabidiol oils, fad diets or supplements where social pressure or users’ expectations can lead to a strong placebo response. Self-blinding citizen science initiatives could be used as an inexpensive, initial screening tool before launching expensive clinical studies.”

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