If research on psychedelics is lacking, then research on long-term effects of microdosing are basically non-existent. I scoured the web and scientific journals for any evidence – and while there are studies on long-term impact of general psychedelic use – there is basically nothing on the long-term effects of using tiny doses of psychedelics.
Mental Health
There have been some meta-analysis studies recently that focused on the effects of general psychedelics use on a large population. Johansen and Krebs (2015) found for example that:
“A recent large population study of 130,000 adults in the United States failed to find evidence for a link between psychedelic use (lysergic acid diethylamide, psilocybin or mescaline) and mental health problems”
And:
“We failed to find evidence that psychedelic use is an independent risk factor for mental health problems. Psychedelics are not known to harm the brain or other body organs or to cause addiction or compulsive use; serious adverse events involving psychedelics are extremely rare. Overall, it is difficult to see how prohibition of psychedelics can be justified as a public health measure.”
Another study, by Hendricks et al. in 2015, found that:
“having ever used any classic psychedelic substance—namely, dimethyltryptamine (DMT), ayahuasca, lysergic acid diethylamide (LSD), mescaline, peyote or San Pedro, or psilocybin—was associated with a significantly reduced likelihood of past month psychological, past year suicidal thinking, past year suicidal planning, and past year suicide attempt in the United States adult population.”
Finally, a study by Bouso et al. in 2012 on the long-term effects of Ayahuasca use, concluded that:
“The assessment of the impact of long-term ayahuasca use on mental health from various perspectives (personality, psychopathology, neuropsychology, life attitudes and psychosocial well-being) did not find evidence of pathological alterations in any of the spheres studied. Although ayahuasca-using subjects differed in some personality traits, differences did not fit with a pathological profile. Furthermore, ayahuasca users showed a lower presence of psychopathological symptoms compared to controls. They performed better in neuropsychological tests, scored higher in spirituality and showed better psychosocial adaptation as reflected by some attitudinal traits such as Purpose in Life and Subjective Well-Being. Overall differences with the control group were still observable at follow-up one year later.”
Overall it would seem that it is difficult to establish the link between long-term psychedelics use and mental health problems. Of course none of this research is specifically link to the risks of microdosing on the long-term, so caution is still advised.
Physical Health
But what about the long-term risks of microdosing on physical health? The risks of people with certain diseases or on certain medication is clear, but what about a healthy individual? Are there downsides to using psychedelics for a healthy human body?
We had some difficulty to find anything of value here, since most of the information focussed on mental health.
There has, however, been some discussion on the relationship between psilocybin and cardiotoxicity. What is meant by this is muscle damage of the heart, meaning that it might be more difficult to pump and circulate blood.
A Reddit user contacted David Nichols, who supposedly emailed back saying:
“Normally, I would not have any concerns about psilocybin, but if you are taking it multiple times per week I think it might not be a good idea until this issue is more fully investigated.” (Link)
Overall, it seems that psychedelics are reasonably safe for long-term use. Especially with regards to mental health, there seem to be little risk of microdosing over a long period. Still, there might be some effects on physical health, but this issue has not been cleared up completely. Unless you are planning on microdosing a few times every week for decades, it doesn’t seem like a major risk for a healthy individual.
Safest Psychedelic for Microdosing
You might be wondering what the safest psychedelic is for long term usage. After looking at user reports and some scientific research for a while, it seems that the traditional psychedelics of psilocybin and LSD are totally fine to use. Designer drugs or research drugs might be less safe due to the fact that no body of knowledge and risks has been built up yet.
The above study by Hendricks et al. (2015) also concluded that:
“among those who have ever used psilocybin suggest that even among the broader class of classic psychedelics, psilocybin may be associated with the greatest therapeutic potential.”
And that:
“This finding is consistent with data indicating that psilocybin may have the most favorable safety profile of all classic psychedelic substances”
While magic mushrooms have been used for centuries, LSD has also been used for decades. And so far no major issues for healthy humans have been found. Interestingly, the LD50 number – which measures the lethal dose for 50% of a population when taking a substance – is incredibly high for both LSD and psilocybin.
For LSD, there isn’t really a way to determine LD50, but estimates are in the 10-12mg range (10,000-12,000 ug), which is more than 100x the normal strength of a dose (100ug).
For psilocybin, the LD50 in rats is 280 mg/kg. A human being of 60kg would need to consume 17 kilos of fresh mushrooms (or 1.7 kilos of dried mushrooms) in order to reach a lethal dose of 50%.
Basically, you would have to try really, really, really hard to give yourself a 50% of a lethal dose on both LSD or psilocybin.
Conclusion
The long-term effects of microdosing on mental health seems negligible, or even positive. For physical health, there don’t seem to be many risks, but some risks might exist (like cardiotoxicity). You might want to consider taking on and off periods, where you stop taking microdoses for a while in order to reduce your risks.