LSD or psilocybin? 
It doesn't matter; the dose is decisive!

A study from Basel shows that this is also true for the acute effects of LSD and psilocybin. They found that the primary differences between the two are dose-dependent, rather than substance-dependent.

In one of the first modern studies to investigate this, Holze et al. 2022 compared both substances in the same study using a within-subjects design. They examined 28 healthy men and women across five separate sessions - each received a placebo, a dose of LSD (100µg and 200µg), and a dose of psilocybin (15mg/30mg) in a random order unknown to both the subject and the study investigators.

During each session, a variety of effects were measured over 24 h, including subjective perceptions (Mood, Altered States of Consciousness), automatic body responses (Blood pressure, heart rate, body temperature and endocrine changes), and the time to onset, time to maximal effect, and effect duration. 

The results confirm the findings of previous studies, but the comparison of the effects of substances and the dosage is particularly interesting (slide 2). The results indicate that alterations of the mind induced by LSD and psilocybin do not differ beyond the duration of their effects (see slide 3); the effects of LSD were significantly longer than those of psilocybin. This shows that any differences between LSD and psilocybin are dose-dependent, rather than substance-dependent, with higher doses producing longer-lasting effects. 

Subjective ratings of the high 30 mg psilocybin dose were nominally between the 100 and 200 μg doses of LSD, indicating that 30 mg psilocybin corresponds to 150 μg LSD base.

As LSD and psilocybin have become promising candidates for treating various psychiatric and neurologic disorders, a deeper understanding of their differential effects in humans is important. These results could help with dose-finding in future studies and enable more direct comparisons when interpreting clinical results.

What do your experiences say? Luckily, dosing is no longer left to guesswork, and you can now easily test it yourself with our miraculix QTests.

Source: Holze, Friederike, et al. "Direct comparison of the acute effects of lysergic acid diethylamide and psilocybin in a double-blind placebo-controlled study in healthy subjects." Neuropsychopharmacology (2022): 1-8.