Microdosing psychedelics like LSD and psilocybin has become popular, but its long-term effects on heart health are unknown. These drugs share structural similarities with medications that raise the risk of cardiac fibrosis and valvulopathy when taken regularly. This review evaluates the evidence that microdosing for months or more could increase the risk of cardiac fibrosis, discusses the role of the 5-HT2B receptor in drug-induced cardiac fibrosis, and recommends safety evaluations for future studies.
A single 100 µg dose of lysergic acid diethylamide (LSD) improved offline motor learning the next day and, one week later, reduced perceived stress and increased aspects of cognitive flexibility in 45 healthy adults. Electroencephalography showed that LSD acutely decreased N1 and P2 auditory event-related potential amplitudes, with P2 still modulated after one week. Transcranial magnetic stimulation revealed increased motor-evoked potential amplitude and faster latency under LSD. Brain-derived neurotrophic factor levels were unchanged. The findings suggest lasting effects of LSD on learning and neural signals, while highlighting challenges in measuring long-term potentiation in humans.