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By: HISTORY.com Editors

Crime

LSD

HISTORY.com Editors

A woman dances in the glow of psychedelic light at Avalon Ballroom in San Francisco.

© Ted Streshinsky/CORBIS/Corbis via Getty Images

Published: June 14, 2017

Last Updated: May 28, 2025

Table of contents

1

Albert Hofmann and Bicycle Day

2

LSD Effects

3

The CIA and Project MK-Ultra

4

Ken Kesey and the Electric Kool-Aid Acid Test

5

Timothy Leary and Richard Alpert

6

Carlos Castañeda and Other Hallucinogens

7

Sources

LSD, or lysergic acid diethylamide, is a hallucinogenic drug that was first synthesized a Swiss scientist in the 1930s. During the Cold War, the CIA conducted clandestine experiments with LSD (and other drugs) for mind control, information gathering and other purposes. Over time, the drug became a symbol of the 1960s counterculture, eventually joining other hallucinogenic and recreational drugs at rave parties.

Albert Hofmann and Bicycle Day

Albert Hofmann, a researcher with the Swiss chemical company Sandoz, first developed lysergic acid diethylamide or LSD in 1938. He was working with a chemical found in ergot, a fungus that grows naturally on rye and other grains.

Hofmann didn’t discover the drug’s hallucinogenic effects until 1943 when he accidentally ingested a small amount and perceived “extraordinary shapes with intense, kaleidoscopic play of colors.”

Three days later, on April 19, 1943, he took a larger dose of the drug. As Hofmann rode home from work on his bicycle—World War II restrictions made automobile travel off-limits—he experienced the world’s first intentional acid trip.

Years later, April 19 came to be celebrated by some recreational LSD users as Bicycle Day.

LSD Effects

LSD is just one mind-altering substance in a class of drugs called hallucinogens, which cause people to have hallucinations—things that someone sees, hears or feels that appear to be real but are in fact created by the mind.

LSD users call these hallucinogenic experiences “trips,” and LSD is a particularly strong hallucinogen. Because its effects are unpredictable, there’s no way to know when taking the drug whether a user will have a good trip or not.

Depending on how much a person takes or how their brain responds, a trip can be pleasurable and enlightening, or, during a “bad trip,” a user may have terrifying thoughts or feel out of control.

Long after they’ve taken the drug, some users experience flashbacks, when parts of the trip return without using the drug again. Researchers think LSD flashbacks may happen during times of increased stress.

The CIA and Project MK-Ultra

Project MK-Ultra, the code name given to a Central Intelligence Agency program that began in the 1950s and lasted through the 1960s, is sometimes known as part of the CIA’s “mind control program.”

Throughout the years of Project MK-Ultra, the CIA experimented with LSD and other substances on both volunteers and unwitting subjects. They believed that LSD could be used as a psychological weapon in the Cold War. Hypnosis, shock therapy, interrogation and other dubious mind-control techniques were also part of MK-Ultra.

These government acid experiments—which also involved dozens of universities, pharmaceutical companies and medical facilities—took place throughout the 1950s and 1960s, before LSD was deemed too unpredictable to use in the field.

When Project MK-Ultra became public knowledge in the 1970s, the scandal resulted in numerous lawsuits and a congressional investigation headed by Senator Frank Church.

Ken Kesey and the Electric Kool-Aid Acid Test

After volunteering to take part in Project MKUltra as a student at Stanford University, Ken Kesey, author of the 1962 novel One Flew Over the Cuckoo’s Nest, went on to promote the use of LSD.

In the early 1960s, Kesey and the Merry Pranksters (as his group of followers were called) hosted a series of LSD-fueled parties in the San Francisco Bay area. Kesey called these parties “Acid Tests.”

Acid Tests combined drug use with musical performances by bands including the Grateful Dead and psychedelic effects such as fluorescent paint and black lights.

Author Tom Wolfe based his 1968 non-fiction book, The Electric Kool-Aid Acid Test, on the experiences of Ken Kesey and the Merry Pranksters. The book chronicles the Acid Test parties and the growing 1960s hippie counterculture movement.

Timothy Leary and Richard Alpert

Both psychology professors at Harvard University, Timothy Leary and Richard Alpert administered LSD and psychedelic mushrooms to Harvard students during a series of experiments in the early 1960s.

At the time, neither of these substances were illegal in the United States. (The U.S. federal government didn’t outlaw LSD until 1968.)

Leary and Alpert documented the effects of the hallucinogenic drugs on the students’ consciousness. The scientific community, however, criticized the legitimacy of the studies which Leary and Alpert conducted while also tripping.

Both men were eventually dismissed from Harvard but went on to become symbols of the psychedelic drug and hippie counterculture.

Leary founded a psychedelic religion based on LSD called the League for Spiritual Discovery and coined the phrase “tune in, turn on, drop out.” Alpert wrote a popular spiritual book called Be Here Now under the pseudonym Baba Ram Dass.

Carlos Castañeda and Other Hallucinogens

Hallucinogens can be found in the extracts of some plants or mushrooms, or they can be manmade like LSD. The ergot fungus, from which Hofmann synthesized LSD in 1938, has been associated with hallucinogenic effects since ancient times.

Peyote, a cactus native to parts of Mexico and Texas, contains a psychoactive chemical called mescaline. Native Americans in Mexico have used peyote and mescaline in religious ceremonies for thousands of years.

There are more than 100 species of mushrooms around the world that contain psilocybin, a hallucinogenic compound. Archeologists believe humans have used these “magic mushrooms” since prehistoric times.

Carlos Castañeda was a reclusive author whose best-selling series of books include The Teachings of Don Juan, published in 1968.

In his writings, Castañeda explored the use of mescaline, psilocybin and other hallucinogenics in spirituality and human culture. Born in Peru, Castañeda spent much of his adult life in California and helped to define the psychological landscape of the 1960s.

A number of manmade hallucinogens, such as MDMA (ecstasy or molly) and ketamine, are sometimes associated with dance parties and “rave culture.” PCP (angel dust) was used in the 1950s as a anesthetic before it was taken off the market in 1965 for its hallucinogenic side effects, only to become a popular recreational drug in the 1970s.

Sources

Hallucinogens. National Institute on Drug Abuse. Timothy Leary. Harvard University Department of Psychology. Harvard LSD Research Draws National Attention. The Harvard Crimson. Substance use – LSD. Medline Plus, National Library of Medicine. Carlos Castaneda, Mystical and Mysterious Writer, Dies. The New York Times.

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HISTORY.com Editors

HISTORY.com works with a wide range of writers and editors to create accurate and informative content. All articles are regularly reviewed and updated by the HISTORY.com team. Articles with the “HISTORY.com Editors” byline have been written or edited by the HISTORY.com editors, including Amanda Onion, Missy Sullivan, Matt Mullen, Christian Zapata and Cristiana Lombardo.

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Citation Information

Article title
LSD
Author
HISTORY.com Editors
Website Name
History
URL
https://www.history.com/articles/history-of-lsd
Date Accessed
June 24, 2025
Publisher
A&E Television Networks
Last Updated
May 28, 2025
Original Published Date
June 14, 2017

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