lysergic acid diethylamide

Lysergic acid diethylamide, commonly known as LSD (from German ) and by the nicknames acid and lucy, is a semisynthetic hallucinogenic drug derived from ergot, known for its powerful psychological effects and serotonergic activity. It was historically used in psychiatry and 1960s counterculture; it is currently legally restricted but receiving renewed scientific interest and increasing use.

LSD taken orally has an onset of action of 0.4 to 1.0hours and a duration of 7 to 12hours. In recreational settings it is commonly administered via tabs of blotter paper. LSD is extremely potent, with noticeable effects at doses as low as 20micrograms and is sometimes taken in even smaller amounts for microdosing. Despite widespread use, no fatal human overdoses have been documented. LSD is mainly used recreationally or for spiritual purposes. LSD can cause mystical experiences. LSD exerts its effects primarily through high-affinity binding to several serotonin receptors, especially the serotonin 5-HT2A receptor, and to a lesser extent dopamine and adrenergic receptors. Neuroimaging studies indicate that LSD reduces the efficacy of thalmo-cortical information filtering, decreases oscillatory power within the default mode network, and flattens hierarchical organization of large-brain activity. At higher doses, it can induce visual and auditory hallucinations, ego dissolution, and anxiety. LSD use can cause adverse psychological effects such as paranoia and delusions and may lead to persistent visual disturbances known as hallucinogen persisting perception disorder (HPPD).