Microdosing: what the current evidence actually shows

Microdosing — the practice of taking very small amounts of a psychedelic substance, below the level expected to produce perceptible changes in consciousness — has become one of the most widely discussed trends in psychedelic science. Enthusiasts report benefits ranging from sharper focus and enhanced creativity to improved mood and emotional balance. But popular enthusiasm has run well ahead of the evidence. A growing body of controlled research, including several placebo-controlled trials, now offers a more cautious picture: the benefits of microdosing may be smaller, less consistent, and harder to separate from the placebo effect than the anecdotal literature suggests.

The term most often refers to substances such as psilocybin or LSD. In South Africa, psilocybin is classified as a Schedule 7 substance under the Medicines and Related Substances Act, making any non-authorised use illegal. SAHPRA, the South African Health Products Regulatory Authority, would oversee any future medical or research access.

What controlled studies have found

Several controlled studies have now tested microdosing under laboratory conditions, and the results are notably mixed. Some have found small improvements in measures of mood, well-being, or cognitive performance; others have found no significant difference between active microdoses and placebo. A 2020 study by Bershad and colleagues, for instance, reported that a low dose of LSD produced modest increases in feelings of well-being and social connection but did not consistently enhance cognitive performance. Other studies have reported improvements in attention or convergent thinking, but effect sizes have generally been modest and sometimes inconsistent across different tasks.

A notable study from the Imperial College Centre for Psychedelic Research used a self-blinding citizen-science design, in which participants prepared their own active and placebo capsules and followed a schedule without knowing which they were taking on a given day. The researchers found that while participants reported benefits overall, those who believed they had taken the active substance reported more improvement — and the ability to distinguish active from placebo doses was associated with stronger perceived benefits. This finding raises the possibility that much of the reported benefit reflects expectancy rather than pharmacological action.

The placebo and expectancy problem

Expectancy — the psychological expectation that a substance will help — is a powerful driver of reported benefit in any drug trial, and microdosing may be especially vulnerable to it. Because microdoses are by definition below the threshold of perceptual effect, participants in trials may not always know whether they have taken an active dose or a placebo. In theory, this should make blinding easier than in full-dose psychedelic studies, where the subjective effects are dramatic. In practice, subtle effects sometimes break the blind, and the self-blinding study found that participants were better than chance at guessing which condition they were in.

Research has also compared people who microdose with people who take placebo doses knowing they are placebos. Some of these studies found that both groups reported similar improvements in well-being and creativity, suggesting that the act of engaging in a microdosing routine — paying attention to one's mental state, keeping a journal, expecting improvement — may account for much of the benefit. This does not mean the benefits are not real, but it complicates the claim that they stem from the substance itself in the way many users assume.

Potential downsides

Microdosing is often assumed to be risk-free, but research suggests caution. Some studies have reported increased anxiety, irritability, or mild physiological discomfort associated with regular low-dose use. There are also open questions about the effects of repeated dosing on serotonin receptors and cardiovascular function, given that psychedelics act on 5-HT2A receptors that are also expressed in blood vessels and heart tissue. The long-term safety profile of chronic, low-dose psychedelic use has not been well established, and most existing studies are short in duration.

Where this leaves us

The evidence on microdosing is still developing, and the strongest finding across the current literature may be that expectancy and the broader ritual of microdosing account for a significant portion of reported benefits. This does not negate individual experiences of improvement, but it complicates the claim that microdosing has a clear, reliable pharmacological mechanism for enhancing cognition or mood. Recent systematic reviews have highlighted that while some individual studies show promise, the overall evidence base remains inconsistent and often does not survive comparison with placebo.

From a policy perspective, the uncertainty cuts both ways. If some benefits are attributable to expectancy and ritual rather than pharmacology, this raises questions about whether Schedule 7 criminalisation — which prevents regulated, quality-controlled access and discourages honest reporting — serves public health. At the same time, the case for medical access based specifically on microdosing is not yet supported by the kind of consistent, placebo-controlled evidence that regulatory bodies such as SAHPRA or the TGA would typically require. What is needed is not more anecdote but more research: larger samples, better blinding, longer follow-up periods, and pre-registered outcome measures.