LSD

LSD (lysergic acid diethylamide) is a potent psychedelic synthesized from lysergic acid, an ergot alkaloid. Albert Hofmann first prepared it in 1938 for Sandoz; its psychoactive properties were discovered in 1943. It gained prominence in the 1950s–1960s and remains illegal in many countries with no approved medical use in the United States.

Pharmacology: LSD is a serotonergic psychedelic. Active doses are in micrograms. It acts mainly as a partial agonist at the 5-HT2A receptor and interacts with other serotonin receptors. Effects begin about 20–90 minutes after ingestion, peak within a few hours, and last 8–12 hours. Tolerance develops quickly; there is little evidence of physical dependence.

Effects: Experiences are highly variable. Common perceptual changes include vivid visuals, altered color and shape, synesthesia, and time distortion. Emotions can shift rapidly; some report insights, while others experience anxiety. The set (mental state) and setting (environment) strongly shape outcomes.

Safety and risks: LSD is not typically physically toxic at common doses, but it can provoke intense psychological reactions, including panic and paranoia. Preexisting psychosis or certain medical conditions can be worsened. Rare cases describe hallucinogen-persisting perception disorder (HPPD). There is no antidote; intoxication usually resolves within hours with support.

Legal status and research: In the United States, LSD is a Schedule I substance and illegal to possess outside approved research. Internationally, it is similarly controlled. Renewed scientific interest has explored psychedelic-assisted therapies for treatment-resistant depression, anxiety around life-threatening illness, PTSD, and substance-use disorders under rigorous screening and monitoring.