In contrast to a regular dose that is characterized by perceptual changes and hallucinations, a microdose by definition does not induce perceptual alterations (Greiner et al., 1958; Vollenweider and Kometer, 2010; Liechti, 2017; thethirdwave, 2018; Yanakieva et al., 2018; K.P.C. Kuypers et al., unpublished observations). The most widely suggested practice is taking one-tenth of a regular, recreational dose of a psychedelic once every 3 days (Fadiman, 2011; thethirdwave, 2018). There is some early research on using low doses of psychedelics (for review, see Passie, 2019); however, motives and side-effects of microdosing with psychedelics among users pmc the exact dose along with the practiced dosing schedule people use today is not known.

Negative Effects of Microdosing

Additionally, earlier studies demonstrated that psychedelics also provided physical symptom relief, for example in patients with pathologic pain (18). Nonetheless, a psychedelic experience, characterized by acute alterations in perception and cognition, and amplified emotional states (19), may not always be necessary in case of the latter, or not preferable based on individuals’ (personality) traits (20) or previous (in)experience with psychedelic substances (21). Furthermore, although physically safe, psychedelic experiences can prove challenging and thus psychological support is encouraged during and after the experience. Taken together, a recreational, full dose can prove costly and impractical for certain disorders, requiring individuals to be supervised in a controlled, clinical environment. Preparation strategies undertaken prior to the psychedelic experience were commonly reported by users and show alignment to historical and clinical research with psychedelic drugs. For example, many users employ strategies aimed at promoting a helpful mindset characterised by ease, acceptance and surrender; and consider the environmental, social (and cultural) setting before taking psychedelics.

Psychedelic microdosing, the practice of taking chronic, sub-hallucinogenic doses of psychedelic compounds on an intermittent schedule, has been gaining popularity, and its potential use in medicine is being increasingly discussed in scientific communities and the popular media. Moreover, it is purported to enhance cognitive performance, facilitate creativity, and improve productivity, properties that would be attractive to those looking to gain a competitive edge in school or the workplace (Glatter 2015). In fact, pharmacological cognitive enhancement is becoming more prevalent throughout the world (Maier, Ferris, and Winstock 2018). While stimulants are the most commonly used drugs for cognitive enhancement, psychedelics have long been suggested as potential pharmacological means for promoting creativity (Sessa 2008), and a recent study by Prochazkova and colleagues (2018) demonstrated that a single microdose can enhance cognitive flexibility. Claims that psychedelic microdosing can enhance cognitive function coupled with the increasing popularity of pharmacological cognitive enhancement, highlight the need to evaluate the potential risks and benefits of this practice through rigorous scientific studies. Harm reduction respects an individual’s autonomy and values, whilst helping them to engage in conscious and informed decision making around drug use.

Microdoses of a Psychedelic

Nonetheless, they have reemerged over the past several decades as medicines with the potential to address mental illness and enhance well-being among largely non-Indigenous communities. Seven out of 27 studies reported use of harm reduction strategies post psilocybin use, known as ‘integration’. Compared to consideration given to preparation strategies, integration strategies were less commonly reported in naturalistic settings. Specific strategies reported included having a friend to talk to, keeping a ‘trip journal’ or writing after the session 37, 46, 51. Further, one study found that higher use of integration strategies was predictive of psychological growth. Individuals who reported reflecting on their psychedelic experience, using their psychedelic experience as a learning opportunity, and incorporating learnings into daily life were more likely to report psychological growth, which encompassed self-development, purpose in life and autonomy 46.

Safety based strategies reported consideration of the substance itself, including making sure the drug was obtained from a trusted source, being ‘careful’ about dosage and using drug testing kits 31, 37, 53. Other safety-focused strategies included telling a friend of planned use, planning travel arrangements for after the session to avoid driving, and not mixing the drug with alcohol, and not dosing if feeling unwell 36, 51, 53. However, several studies found that poly-drug use was also common suggesting not all users consider the increased risk of poly substance use when taking psychedelic drugs 31, 33.

• The concepts of set and setting when curating an optimal psychedelic experience are not new, dating back to the original period of Western psychedelic research from the 1950’s 58.
• Nonetheless, a psychedelic experience, characterized by acute alterations in perception and cognition, and amplified emotional states (19), may not always be necessary in case of the latter, or not preferable based on individuals’ (personality) traits (20) or previous (in)experience with psychedelic substances (21).
• Commonly reported intentions for use were self-expansion motives such as expanded awareness or learning about the self, self-treatment of mental health issues, self enhancement, or purely recreational and hedonistic intentions 21, 39, 48.
• The inclusion of a large and comparable group of non-microdosers for the purpose of comparison is another strength and allowed a detailed examination of the associations between microdosing and mental health.

Data base search procedure

The most reported negative effects were of psychological nature and occurred acutely while under the influence. To conclude, this study demonstrates that SRE of MDP to alleviate symptoms of a range of mental or physiological diagnoses is higher compared to conventionally offered treatment options and lower than regular (‘full’) psychedelic doses. Future RCTs in patient populations will be able to answer questions of these effectivity claims of psychedelics, whether these are dose related, disorder specific, and superior to conventional treatments.

Knowledge was sought from several sources including the users’ own experiences, from friends, online forums, and academic peer reviewed articles 36, 46. Interestingly, users reported being less likely to seek information from their health care providers, and government sources of information were less likely to be trusted than other sources 32. The authors suggested that this is likely due to historical misrepresentation from government agencies regarding the true risks of psychedelic substances 32.

The most frequently reported psychedelics used, both in regular and microdoses, were LSD and psilocybin. The most reported regular and microdose for LSD was 200 mcg and 10 mcg, and for psilocybin 3.5 g and 0.5 g, respectively. In addition, one-half of the respondents (48.9%) that microdosed followed their own microdosing schedule. The majority of respondents who microdosed with LSD and psilocybin (57–78%) reported using microdosing several times per week, ranging between 2 and 4 times per week, respectively.

Chi-square tests of independence were calculated comparing the frequency of reasons to stop per dose (regular/micro). The Global Drug Survey 2018 (GDS2018) reported that last year’s prevalence of LSD microdosing among their respondents was 28.6% (Winstock et al., 2018). However, scientific data on the prevalence of microdosing with psychedelics other than LSD as well as the prevalence of microdosing in the work environment are lacking. Psilocybin mushrooms are the most often used among psychedelic drugs, according to a report by the nonpartisan Rand research group.

• The nonprofit Fireside Project offers free phone support for people during a psychedelic experience and has received hundreds of calls about microdosing.
• This finding aligns with previous suggestions from research in clinical settings which has found that sensitivity to context is increased whilst in the psychedelic state 56.
• Further research which recognises the varying motivations of psychedelic users whilst recommending appropriate strategies for preparation, during the experience and post usage (integration) is needed.
• In general, our findings highlight the diversity of practices gathered under the umbrella of microdosing.
• On the contrary, other users who report expansion intentions describe having the experience outside in nature, or in ceremonial settings with other participants present.

The level of education consisted of three pre-set categories; primary (e.g. elementary school), secondary (e.g. high school, academies, gymnasium) and tertiary education (e.g. university, trade school, college). The nonprofit Fireside Project offers free phone support for people during a psychedelic experience and has received hundreds of calls about microdosing. One small study did find glimmers of an effect of small LSD doses on vigor and elation in people with mild depression when compared with a placebo. When free text was entered, the response was manually re-classified in the best matching category. The potential has spurred an Australian company to conduct early trials of microdoses of LSD for severe depression and in cancer patients experiencing despair.

Table 2.

Response options assessing motives were generated based on previous research11–13 and consultation with experts in the field. Following completion of the baseline survey, participants were invited to follow a separate link within the app to complete the Depression, Anxiety, Stress Scale-21 (DASS-21)33. The DASS-21 contains three subscales assessing Depression, Anxiety and Stress each of which has 7-items scored from 0 to 3, to assess symptom severity during the past week. The antidepressant and anxiolytic clinical effects of psychedelics have been hypothesized to result from the psychoplastogenic effects of these drugs (Olson 2018). Psychedelics promote the growth of dendritic branches, spines, and synapses in the prefrontal cortex (PFC). The PFC is a critical brain region responsible for modulation of circuits implicated in mood and anxiety.

Microdosing with psychedelics has gained considerable media attention where it is portrayed as a performance enhancer, especially popular on the work floor. While reports are in general positive, scientific evidence about potential negative effects is lacking aside from the prevalence and motives for use. The present study addressed this gap by surveying psychedelic users about their experience with microdosing including their dosing schedule, motivation, and potential experienced negative effects.

Psychedelic Microdosing: Prevalence and Subjective Effects

Commonly reported intentions for use were self-expansion motives such as expanded awareness or learning about the self, self-treatment of mental health issues, self enhancement, or purely recreational and hedonistic intentions 21, 39, 48. Research which focussed on recreational motivations discussed the ‘pleasures’ of the psychedelic state itself including fun, performativity, connection, and activities such as dancing 42, 47. Other studies which highlighted self-expansion or self-treatment focussed more on the preparatory strategies and ways to enhance the benefits of the psychedelic state 35, 51. These findings suggest that differing intentions for use may inform different harm reduction or benefit enhancing strategies.

Preferred reporting items for systematic reviews and meta-analyses extension for scoping reviews (PRISMA-ScR) Checklist

Future experimental placebo-controlled studies are needed to test whether performance enhancement can be quantified and to assess potential negative effects after longer term microdosing. Interestingly, OCD was not rated to be more effective on any of the questions compared to conventional treatments, and while anecdotal evidence is inconclusive about the effects of MDP on OCD (27), this might indicate that MDP is not effective in treating OCD. In order to understand these differences in SRE of MDP for different disorders, RCTs are needed to objectively examine the reported effects as well as the underlying mechanisms.