Lysergic acid diethylamide

Lysergic acid diethylamide (LSD)
INN: Lysergide
2D structural formula and 3D models of LSD
Clinical data
Pronunciation/daɪ eθəl ˈæmaɪd/, /æmɪd/, or /eɪmaɪd/[3][4][5]
SynonymsLSD, LSD-25, Acid, Delysid, others
  • US: C (Risk not ruled out)
Routes of
By mouth, under the tongue, intravenous
Drug classHallucinogen (serotonergic psychedelic)
ATC code
  • None
Legal status
Legal status
Pharmacokinetic data
Protein bindingUnknown[7]
MetabolismLiver (CYP450)[6]
Onset of action30–40 minutes[8]
half-life3.6 hours[6][9]
Duration of action8–12 hours[10]
50-37-3 ☑Y
DB04829 ☑Y
5558 ☑Y
CHEBI:6605 ☑Y
ChEMBL263881 ☑Y
100.000.031 Edit this at Wikidata
Chemical and physical data
Molar mass323.44 g·mol−1
3D model (Interactive image
Melting point80 to 85 °C (176 to 185 °F)

Lysergic acid diethylamide (LSD), also known as acid, is a hallucinogenic drug.[11] Effects typically include altered thoughts, feelings, and awareness of one's surroundings.[11] Many users see or hear things that do not exist.[12] Dilated pupils, increased blood pressure, and increased body temperature are typical.[13] Effects typically begin within half an hour and can last for up to 12 hours.[13] It is used mainly as a recreational drug and for spiritual reasons.[13][14]

While LSD does not appear to be addictive, tolerance with use of increasing doses may occur.[11][15] Adverse psychiatric reactions such as anxiety, paranoia, and delusions are possible.[7] Distressing flashbacks, a condition called hallucinogen persisting perception disorder, may occur despite no further use.[16][17] Death as a result of LSD is very rare, though occasionally occurs via accidents.[13] The effects of LSD are believed to occur as a result of alterations in the serotonin system.[13] As little as 20 micrograms can produce an effect.[13] In pure form LSD is clear or white in color, has no smell, and is crystalline.[11] It breaks down with exposure to ultraviolet light.[13]

In the United States, as of 2017, about 10% of people have used LSD at some point in their life, while 0.7% have used it in the last year.[12] It was most popular in the 1960s to 1980s.[13] LSD is typically either swallowed or held under the tongue.[11] It is most often sold on blotter paper and less commonly as tablets or in gelatin squares.[13] There are no known treatments for addiction, if it occurs.[16]

LSD was first made by Albert Hofmann in 1938 from lysergic acid, a chemical from the fungus ergot.[13][16] Hofmann discovered its hallucinogenic properties in 1943.[18] In the 1950s, the Central Intelligence Agency (CIA) believed the drug might be useful for mind control so tested it on people, some without their knowledge, in a program called MKUltra.[19] LSD was sold as a medication for research purposes under the trade-name Delysid in the 1950s and 1960s.[13][20] It was listed as a schedule 1 controlled substance by the United Nations in 1971.[13] It currently has no approved medical use.[13] In Europe, as of 2011, the typical cost of a dose was between €4.50 and €25.[13]



Pink elephant blotters containing LSD

LSD is commonly used as a recreational drug.[21]


LSD is considered an entheogen because it can catalyze intense spiritual experiences, during which users may feel they have come into contact with a greater spiritual or cosmic order. Users sometimes report out of body experiences. In 1966, Timothy Leary established the League for Spiritual Discovery with LSD as its sacrament.[22][23] Stanislav Grof has written that religious and mystical experiences observed during LSD sessions appear to be phenomenologically indistinguishable from similar descriptions in the sacred scriptures of the great religions of the world and the texts of ancient civilizations.[24]


LSD currently has no approved uses in medicine.[25][26] A meta analysis concluded that a single dose was effective at reducing alcohol consumption in alcoholism.[27] LSD has also been studied in depression, anxiety, and drug dependence, with positive preliminary results.[28]

Other Languages
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български: ЛСД
bosanski: LSD
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فارسی: ال‌اس‌دی
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hrvatski: Lizergid (LSD)
Bahasa Indonesia: Asam lisergat dietilamida
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русский: ЛСД
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srpskohrvatski / српскохрватски: Dietilamid liserginske kiseline
suomi: LSD
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Türkçe: LSD
українська: ЛСД
Tiếng Việt: LSD