Lysergic acid diethylamide (LSD), widely known as “acid,” is a potent synthetic psychedelic substance. It is derived from lysergic acid, which originates from ergot, a fungus that grows on rye and other grains. LSD is recognized for its powerful effects on perception, mood, and thought processes. It belongs to a class of hallucinogens, which can significantly alter an individual’s sensory experiences and sense of reality.
Journey to the Brain
LSD is typically administered orally, often absorbed from blotter paper, sugar cubes, or gelatin sheets. It can also be found in liquid or capsule forms. Once ingested, the substance is absorbed into the bloodstream.
From the bloodstream, LSD must cross the blood-brain barrier to reach the central nervous system. This barrier is a protective network of tightly packed cells that regulates the passage of substances from the blood into the brain. LSD’s chemical structure allows it to bypass this barrier, enabling it to interact with brain cells and initiate its effects.
Interacting with Neurotransmitters
Upon entering the brain, LSD primarily interacts with neurotransmitter systems, particularly serotonin. Its main mechanism of action involves acting as an agonist at serotonin receptors, meaning it binds to and activates them. The 5-HT2A serotonin receptor is a key target for LSD, and its activation is a primary driver of the psychedelic effects.
While the interaction with 5-HT2A receptors is central, LSD also exhibits affinity for other serotonin receptor subtypes, as well as dopamine and adrenergic receptors. This broader interaction profile contributes to the range of effects. Alterations in perception and cognition are largely attributed to its engagement with the 5-HT2A receptor system.
Brain Activity and Perception
The interactions of LSD with serotonin receptors lead to changes in brain activity, influencing perception, thought, and emotion. Research indicates that LSD alters the connectivity within neural networks. It increases communication between brain regions that typically operate independently, such as the visual cortex.
These altered communication patterns may underlie perceptual phenomena like synesthesia, where sensory experiences blend (e.g., “seeing sounds” or “hearing colors”). The drug can also affect one’s sense of self and distort time perception, leading to experiences where moments feel extended or compressed. These effects stem directly from the drug’s molecular interactions, leading to a reorganized processing of sensory and cognitive information.
Duration and Clearance
The effects of LSD typically begin 20 to 90 minutes after oral administration. The psychedelic experience commonly lasts 7 to 12 hours. However, full effects can extend up to 22 hours, depending on dosage and individual factors.
The body metabolizes and eliminates LSD primarily through the liver. Enzymes in the cytochrome P450 system break down the substance into metabolites. These metabolites are then excreted, predominantly through urine and, to a lesser extent, via bile.