By: HISTORY.com Editors

1943

Hallucinogenic effects of LSD discovered

HISTORY.com Editors

Published: November 24, 2009

Last Updated: May 28, 2025

In Basel, Switzerland, Albert Hofmann, a Swiss chemist working at the Sandoz pharmaceutical research laboratory, accidentally consumes LSD-25, a synthetic drug he had created in 1938 as part of his research into the medicinal value of lysergic acid compounds. After taking the drug, formally known as lysergic acid diethylamide, Dr. Hofmann was disturbed by unusual sensations and hallucinations. In his notes, he related the experience:

This Day In History: 04/16/1943 - Effects of LSD Discovered

LSD the hallucinogenic is discovered, Lenin returns to Russia during the Russian Revolution, Mick Jagger and the Rolling Stones release their first album, and Wayne Gretzky retires from hockey in This Day in History video. The date is April 16th. Vladimir Lenin, a Russian revolutionary, is famous for initiating what many call the October Revolution.

“Last Friday, April 16, 1943, I was forced to interrupt my work in the laboratory in the middle of the afternoon and proceed home, being affected by a remarkable restlessness, combined with a slight dizziness. At home I lay down and sank into a not unpleasant, intoxicated-like condition characterized by an extremely stimulated imagination. In a dreamlike state, with eyes closed (I found the daylight to be unpleasantly glaring), I perceived an uninterrupted stream of fantastic pictures, extraordinary shapes with intense, kaleidoscopic play of colors. After some two hours this condition faded away.”

After intentionally taking the drug again to confirm that it had caused this strange physical and mental state, Dr. Hofmann published a report announcing his discovery, and so LSD made its entry into the world as a hallucinogenic drug. Widespread use of the so-called “mind-expanding” drug did not begin until the 1960s, when counterculture figures such as Albert M. Hubbard, Timothy Leary and Ken Kesey publicly expounded on the benefits of using LSD as a recreational drug. The manufacture, sale, possession and use of LSD, known to cause negative reactions in some of those who take it, were made illegal in the United States in 1965.

Timeline

Also on This Day in History

Discover more of the major events, famous births, notable deaths and everything else history-making that happened on April 16th

1881

Western gunslinger, Bat Masterson, fights in last shootout

On the streets of Dodge City, famous western lawman and gunfighter Bat Masterson fights what is the last documented gun battle of his life. Bartholomew “Bat” Masterson had made a living with his gun from a young age. In his early 20s, Masterson worked as a buffalo hunter, operating out of the wild Kansas cattle […]

2:42m read

1889

Hollywood legend Charlie Chaplin born

On April 16, 1889, future Hollywood legend Charlie Chaplin is born Charles Spencer Chaplin in London, England. Chaplin, one of the most financially successful stars of early Hollywood, was introduced to the stage when he was five. The son of London music hall entertainers, young Chaplin was watching a show starring his mother when her […]

2:36m read

1917

Lenin returns to Russia from exile

On April 16, 1917, Vladimir Lenin, leader of the revolutionary Bolshevik Party, returns to Petrograd after a decade of exile to take the reins of the Russian Revolution. Born Vladimir Ilyich Ulyanov in 1870, Lenin was drawn to the revolutionary cause after his brother was executed in 1887 for plotting to assassinate Czar Alexander III. […]

3:40m read

1929

Cleveland becomes first MLB team to play with numbers on back of jerseys

On April 16, 1929, the Cleveland Indians open the season with numbers on the back of each player’s jersey, the first Major League Baseball team to do so. The numbers make it easier for scorekeepers, broadcasters and fans to identify players. Cleveland wins the game against the Detroit Tigers in 11 innings, 5-4. The New York […]

1:12m read

1945

Hitler calls for last stand on the Eastern front

On April 16, 1945, Adolf Hitler proclaims from his underground bunker that deliverance was at hand from encroaching Russian troops—and that his beloved capital city of Berlin would remain German. A “mighty artillery is meeting the enemy,” proclaims Der Fuhrer. “This time the Bolsheviks will experience Asia’s old fate. That is, he must and will bleed […]

0:48m read

1946

Arthur Chevrolet dies by suicide

On April 16, 1946, Arthur Chevrolet, an auto racer and the brother of Chevrolet auto namesake Louis Chevrolet, dies by suicide in Slidell, Louisiana. Louis Chevrolet was born in Switzerland in 1878, while Arthur’s birth year has been listed as 1884 and 1886. By the early 1900s, Louis and Arthur, along with their younger brother […]

1:52m read

1947

Fertilizer explosion kills more than 500 in Texas

A giant explosion occurs during the loading of fertilizer onto the freighter Grandcamp at a pier in Texas City, Texas, on April 16, 1947. Nearly 600 people lost their lives and thousands were injured when the ship was literally blown to bits. Ammonium nitrate was used as an explosive by the U.S. Army in World […]

2:06m read

1947

Bernard Baruch popularizes the term “Cold War”

Multimillionaire and financier Bernard Baruch, in a speech given during the unveiling of his portrait in the South Carolina House of Representatives, coins the term “Cold War” to describe relations between the United States and the Soviet Union. The phrase stuck, and for over 40 years it was a mainstay in the language of American diplomacy. […]

1963

Martin Luther King Jr. writes “Letter from a Birmingham Jail”

On April 16, 1963, days after being jailed in Birmingham, Alabama, for a series of anti-segregation protests, Dr. Martin Luther King, Jr. pens a response to his critics on some scraps of paper. This open letter, now known as his “Letter from a Birmingham Jail,” offered a forceful defense of the protest campaign. It is […]

2:22m read

1972

Apollo 16 departs for moon

From Cape Canaveral, Florida, Apollo 16, the fifth of six U.S. lunar landing missions, is successfully launched on its 238,000-mile journey to the moon. On April 20, astronauts John W. Young and Charles M. Duke descended to the lunar surface from the Command Module, which remained in orbit around the moon with a third astronaut, […]

0:46m read

2007

Virginia Tech shooting leaves 32 dead

32 people died after being gunned down on the campus of Virginia Tech by Seung-Hui Cho, a student at the college.

1:58m read

Virginia Tech vigil

2018

Kendrick Lamar becomes the first rapper to win the Pulitzer Prize

On April 16, 2018, the Pulitzer Prize Board awards the Pulitzer Prize for Music to rapper Kendrick Lamar for his 2017 album, DAMN. It was the first time the award had gone to a musical work outside the genres of classical music and jazz, a watershed moment for the Pulitzers and Lamar and a sign […]

Related Articles

Yellow tape measure with a variety of weight loss medication on blue background.

Inventions & Science

America's Up-and-Down History With Weight-Loss Drugs

From thyroid hormones to amphetamine to the “fen-phen” craze, weight-loss drugs have emerged and continuously faced scrutiny, largely due to unintended health effects.

Why the US Made Marijuana Illegal

Fear of Mexican immigrants led to the criminalization of marijuana.

Activists and family members of loved ones who died in the opioid/heroin epidemic march in a "Fed Up!" rally on the National Mall on September 18, 2016.

America’s War on Drugs Was Designed to Fail. So Why Is It Being Revived Now?

While much of the media is focused on Trump’s Russian skullduggery, America has quietly found itself enmeshed in the worst drug epidemic in our history. Drug overdoses, mostly from increasingly lethal opioids, now kill more people than guns and traffic accidents. A recent investigation by The New York Times of local and state authorities across the […]

Joaquin "El Chapo" Guzman, the world's most wanted-drug trafficker, center, is escorted by Mexican security forces at a Navy hangar in Mexico City, Mexico, on Friday, Jan. 8, 2016. (Credit: Susana Gonzalez/Bloomberg via Getty Images)

8 Times America’s War on Drugs Was Stranger Than Fiction

When the United States first launched the “War on Drugs” in the mid-20th century, not even the cleverest conspiracy theorists could have imagined the far-reaching consequences the campaign would have around the world. From the CIA allowing drug traffickers to flourish in exchange for their assistance in toppling leftist leaders abroad to the deal made […]

See All Articles

About the author

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.

Fact Check

We strive for accuracy and fairness. But if you see something that doesn't look right, click here to contact us! HISTORY reviews and updates its content regularly to ensure it is complete and accurate.

Citation Information

Article title: Hallucinogenic effects of LSD discovered
Author: HISTORY.com Editors
Website Name: History
URL: https://www.history.com/this-day-in-history/april-16/hallucinogenic-effects-of-lsd-discovered

Date Accessed: July 04, 2025
Publisher: A&E Television Networks
Last Updated: May 28, 2025
Original Published Date: November 24, 2009

History Every Day

Sign Up for "This Day in History"

Uncover fascinating moments from the past every day! Learn something new with key events in history, from the American Revolution to pop culture, crime and more.

By submitting your information, you agree to receive emails from HISTORY and A+E Global Media. You can opt out at any time. You must be 16 years or older and a resident of the United States.

More details: Privacy Policy | Terms of Use | Contact Us