risks of microdosing

Risks of Microdosing

One of the most frequently asked questions about microdosing is: is microdosing safe? In other words, what are the risks of microdosing? After all, we heard disturbing stories about LSD and magic mushrooms, psychoses, acute schizophrenia, and flashbacks. These stories date to the 1960s and are primarily attributed to exaggerated propaganda from the War on Drugs.

Meanwhile, the risks of psychedelics in a high dosage have been well studied and documented. As it turns out, psychedelics are among the safest substances on the “drugs” spectrum—below weed, alcohol, and MDMA.

It’s tempting to assume that when microdosing — taking a tiny or micro amount of a psychedelic substance — that the risk will also become smaller. However, this is a false assumption, and anecdotal evidence does show that microdosing can have some risks. Our understanding of the direct physiological effects of microdosing is currently limited, but gaining ground as more clinical studies on the practice are taking place. For now, we must rely on what we know about higher dosages as well as the side effects, and contraindications reported by the experimental microdosers.

A provisional starting point for the risks of microdosing

Dr. James Fadiman and Sophia Korb have collected over 1850 reports of experiences from microdosers across 59 countries. In these reports, there were only 75 people in total that claimed not to have a positive experience when microdosing. From this, Fadiman and Korb are confident to a provisional starting point for the risks of microdosing – microdosing is overwhelmingly safe for most people.

Among Fadiman’s gathered responses of microdosers, there was not a single case of  reported psychosis, a risk that requires strong consideration when taking a high dose. However, while no known anecdotal reports exist, it is important to note that this does not rule out the possibility of psychosis triggered by microdosing. It is important to note that the risks of microdosing depend on the specific situation, person, and substance, and therefore it’s best to proceed with caution. 

The most well-known risks of microdosing are:

  • Increased anxiety
  • Increased paranoia in those prone to paranoia
  • Increased emotional instability in those experiencing intense emotional distress such as grief
  • Mild stomach upset and nausea while microdosing psilocybin
  • Fatigue, mainly reported while microdosing psilocybin (see the Nightcap protocol)
  • Difficulties sleeping
  • Psilocybin can cause headaches in some people
  • People diagnosed with bipolar disorder reported that they benefited from microdosing during their depressive phase but would discourage it during a manic phase

Lesser known risks of microdosing include:

Visual tracers in men with color blindness

In Dr. Fadiman’s collected reports, some men with color blindness reported seeing tracers in their field of view. Sometimes those images or lingering colors persisted for days. Not all people with color blindness experienced this, but there is a chance that it will occur.

Long-term microdosing may exacerbate pre-existing heart conditions

One potential concern for microdoses of LSD in people with pre-existing heart conditions, which comes from studies demonstrating that fenfluramine, when taken daily, doubles the risk of Valvular Heart Disease. Fenfluramine binds to the same receptors as LSD and psilocybin, but the quantities used for microdosing are extremely low in comparison. More research is needed to know if this potential risk effectively translates to humans who microdose with LSD or psilocybin.

The current stance by microdosing experts is that the microdosing protocols of 10-weeks, with a 4-week pause afterwards, are generally considered safe for those with pre-existing heart conditions. If you have a pre-existing heart condition, it’s advised to avoid extended periods of microdosing.


People experiencing tinnitus have reported that their tinnitus (ringing in the ears) worsened during microdosing, it didn’t stop their tinnitus, or it stayed the same.

Therefore, when is microdosing not recommended?

  • For people under the age of 18 
  • In combination with alcohol or other drugs
  • During pregnancy or breastfeeding
  • In combination with lithium carbonate medicine (Lithium) or Tramadol
  • Those with a family history of psychosis
  • During periods of intense emotional instability, such as grief
  • Men with color blindness
  • Those who suffer from paranoia/suspicion
  • Those who suffer from tinnitus
  • Those with anxiety or an anxiety disorder. The fear can be magnified, or they become more aware of their fear. On the other hand, for people who suffer from depression and have anxiety, it can help to ease their fears.

General note: the full spectrum of potential risks of microdosing alongside mental or physical disorders are not yet sufficiently known.

What do we know safety and microdosing?

  • Many medications and supplements can be safely combined with microdosingNOTE: This statement only applies to microdosing, not for higher dosages. Psychedelics containing MAO inhibitors, such as ayahuasca, shouldn’t be combined with some medications.
  • “Set and setting” are not microdosing requirements, but microdosing with a good mindset and proper setting can work to your advantage.
  • Due to lack of understanding on long-term effects of microdosing, it is recommended to avoid microdosing every day.
  • Completing multiple microdosing cycles throughout your life probably doesn’t cause any harm. Albert Hofmann has microdosed the last decades of his life (to the age of 102) to his satisfaction. 

Are these findings and comments decisive when it comes to safety? We don’t think so. The long-term effects of microdosing are not yet known. Dr. James Fadiman especially wants to emphasize that the benefits of microdosing far outweigh the risks. And not all disadvantages mentioned are also a risk of microdosing: some might be merely a point of attention or something to consider.

Risks of Microdosing Graphic

Other potential pitfalls with microdosing:

  • Taking a dose that is too high can cause discomfort during your daily activities. Learn how to find your optimal dose or ‘sweet spot’ here.
  • Those predisposed to periods of anxiety have frequently reported that they felt okay with microdosing, but they felt depressed in the weeks they didn’t microdose. 
  • When microdosing too often (every day), the body builds tolerance, meaning you have to take more to achieve the same effect. Tolerance for LSD  psilocybin and mescaline has not been demonstrated. Adhering to a microdosing protocol can help prevent tolerance build-up.
  • Without microdosing, you no longer feel cheerful, creative, or productive enough. As a result, you become psychologically dependent on microdosing. 

Microdosing in combination with medication

Another frequently asked question related to the risks of microdosing is if microdosing can be combined with medication and supplements. Dr. James Fadiman and Sophia Korb have compiled a list of medications and supplements that—to date—have not been reported to cause any adverse side effects when combined with microdosing.

This list is a result of their long-term research with hundreds of subjects worldwide who have microdosed independently with (mainly) LSD1P-LSD, and psilocybin.  We want to emphasize that this list does not guarantee that you can microdose safely and responsibly while taking any medications listed.

While some may feel that microdosing is a better alternative to other medications, always consult your doctor first if you plan to combine, stop or phase out any medication.

Have you experienced any interactions with microdosing in combination with your medication(s)?  Please, let us know

What do experts say about the risks of microdosing?

David Presti, professor of neurobiology at the University of California, Berkeley, and expert on the effects of drugs on the brain, stated that microdosing is much safer than taking antidepressants. James Rucker, a psychiatrist affiliated with King’s College London, has called for psychedelics to be reclassified—making them better examined and more available to researchers. However, he’s cautious. In the interview with BBC, he said: “If you look at the medical side of microdosing, we don’t know anything yet. We don’t know the long-term effects yet”.

It becomes clear that microdosing needs to be recognized by (medical) researchers and the authorities to be further examined. Dr. Fadiman thinks this won’t take very long; “As long as we continue to find that microdosing has a very beneficial benefit-risk ratio, we expect more pressure from the medical world to use [microdosing] with complaints or disorders that we have not been able to help so far”.

The Trimbos Institute is a Dutch independent knowledge institute for alcohol, tobacco, drugs and mental health. They don’t recommend experimenting with LSD itself. “It is very difficult to measure what exactly microdosing is. You may want to take 10 micrograms, but it may also be that the drop of LSD is not evenly distributed over the seal. Then you take a lot more than you think. Also, there are resources that are sold as LSD, but contain other trip products. There is also a risk there.”

In a perfect world, I think we would microdose LSD instead of giving teenagers Adderall. But I'd like to see it studies first.

Ayelet Waldman

More research needed

It becomes clear that microdosing needs to be recognized by (medical) researchers and the authorities and be further examined. In other words, we need more research. Dr. Fadiman thinks this won’t take very long; “As long as we continue to find that microdosing has a very beneficial benefit-risk ratio, we expect more pressure from the medical world to use this in people with complaints or disorders that we have not been able to help so far”.


The content on this website and the other Microdosing Institute channels is for informational and educational purposes only, and does not substitute professional medical advice or consultation with healthcare professionals. If you are seeking medical advice, diagnose, or treatment, we advise you to consult a medical professional or healthcare provider. Equally, we cannot help with the sourcing of illegal substances.