The Risks of Microdosing: What You Should Know

Microdosing — taking very small amounts of psychedelics such as LSD or psilocybin — has gained popularity in recent years. People often report improved focus, creativity, or mood. Yet alongside the enthusiasm, it’s essential to maintain an informed view of the possible risks.
This article explores what is currently known about the risks of microdosing: psychological, physical, and cardiovascular, as well as for specific vulnerable groups. It draws on the work of James Fadiman and Jordan Gruber, and on research data from the Microdosing Institute (MDI).

What Is Microdosing?

Before discussing risks, it helps to define microdosing: the ingestion of sub-hallucinogenic amounts of a psychedelic substance — not enough to induce a full “trip,” but enough to produce subtle changes.
Fadiman and Gruber describe variations in frequency, dose, and intention (creativity, emotional balance, cognitive clarity) in their book (Fadiman & Gruber, 2021).
Dosage, individual health, mental state, and context all play major roles in a person’s risk profile.

Where Do the Main Risks Lie?

Psychological Risks

According to the Microdosing Institute, the most commonly reported psychological side effects include increased anxiety, heightened paranoia in predisposed individuals, emotional instability during stressful periods, and disrupted sleep (Microdosing Institute, n.d.).
Although many people report improvements, no large-scale controlled studies have yet ruled out negative psychological outcomes — especially in the long term (Fadiman & Gruber, 2021).
Extra caution is advised for people with a history of psychosis or bipolar disorder.

Physical and Cardiovascular Risks

Another important concern is the potential effect of psychedelics on the cardiovascular system.
Certain psychedelics interact with the serotonin receptor 5-HT₂B, long-term activation of which has been associated with heart valve abnormalities and fibrosis (Microdosing Institute, n.d.).
While little human research exists for microdosing, animal studies suggest that such theoretical risks should not be ignored.
A pre-clinical mouse study found no significant cardiac changes after LSD microdosing over a short period — a reassuring finding, though not directly applicable to humans or long-term use (Microdosing Institute, n.d.).

Risks Related to Dosing Uncertainty and Substance Purity

In real-world use, another risk arises from uncertainty about dose accuracy and substance purity. This is especially true for LSD, where precisely dividing microgram quantities is notoriously difficult (Welt.de, 2023).
MDI explicitly discourages combining psychedelics with other drugs, alcohol, or medication such as lithium, and warns against use during pregnancy or breastfeeding (Microdosing Institute, n.d.).

Tinnitus: Both a Potential Benefit and a Possible Risk

One noteworthy point emerging from the MDI community is tinnitus (ringing in the ears).
Data from the international research project Microdose.me (Walsh, 2023) show that some participants with tinnitus actually reported a reduction in symptoms during microdosing — suggesting potential benefits for certain individuals.
At the same time, the Microdosing Institute has collected anecdotal reports from community members who experienced a worsening of tinnitus while microdosing.
Because MDI actively collaborates with researchers to document these contrasting outcomes, the organization was among the first to publicly identify this potential risk.
The underlying cause remains unclear — it may relate to dosage, serotonin sensitivity, or individual stress response.
Given the limited and sometimes conflicting data, tinnitus should be regarded as both a potential benefit and a possible risk that requires further study.

Groups for Whom Microdosing Is More Risky

According to MDI, microdosing is not recommended for:

Individuals under 18
Use in combination with alcohol or other drugs
Pregnancy or breastfeeding
Those with a family history of psychosis
Periods of acute emotional trauma or instability
People with known heart or valve conditions
(Microdosing Institute, n.d.)

What Do Fadiman & Gruber Say?

In Microdosing for Health, Healing and Enhanced Performance, Fadiman and Gruber provide a comprehensive overview of microdosing’s history, research, and self-reported outcomes (Fadiman & Gruber, 2021).
They note that while many participants report positive effects, this does not mean microdosing is risk-free.
Self-monitoring, integration, and awareness of contraindications are essential. Their conclusions are based on thousands of anecdotal reports, but these do not replace controlled clinical trials.

Practical Advice for Those Considering Microdosing

For readers exploring microdosing, consider the following practical safety steps:

Keep a logbook: Record date, dose, effects, and any side effects — patterns become clearer over time.
Start extremely low: Especially in early attempts, and monitor closely.
Plan rest periods: Many protocols recommend breaks to avoid tolerance.
Be realistic: Microdosing is not a shortcut or miracle; results vary widely.
Avoid combining with medication or other psychoactive substances without professional advice.
Check legality and source safety: Regulations differ by country, and unregulated products carry additional risks.

Why Risk Awareness Matters

There’s good reason for excitement around microdosing — some studies link it to improvements in mood, creativity, and cognitive flexibility (John Hopkins, 2021).
However, enthusiasm should not overshadow caution. As the MDI website states:

“The risks of microdosing depend on the specific situation, person, and substance … the full scope of risks remains unknown.” (Microdosing Institute, n.d.)
By fostering awareness of these nuances, users can make more informed decisions — and the field can evolve with greater responsibility.

Conclusion

Microdosing holds promising potential, but it is certainly not without risks. Psychological side effects such as increased anxiety, physical and cardiovascular concerns, tinnitus variability, dosing uncertainty, and drug interactions all call for prudence.
Both Fadiman & Gruber (2021) and the Microdosing Institute emphasize that education, self-awareness, and responsible use are key.
If you are considering microdosing, approach it with respect, preparation, and reflection. Take your personal health seriously, and seek professional guidance where needed.

The information in this article is for educational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional before making changes to medication or mental-health treatment.

References

Fadiman, J., & Gruber, J. (2021). Microdosing for Health, Healing and Enhanced Performance. Center for Minds.
Microdosing Institute. (n.d.). Risks, safety & side effects of microdosing. Retrieved from microdosinginstitute.com
Microdosing Institute. (n.d.). Risk: chronic psychedelic microdosing & valvular heart disease. Retrieved from microdosinginstitute.com
Welt.de. (2023). LSD: Besser drauf, konzentrierter, kreativer … ohne Rausch? Retrieved from welt.de
Walsh, Z. et al. (2023). Microdose.me Research Results Summary. Retrieved from microdose.me