The Swiss chemist discovered lysergic acid diethylamide-25 in 1938 while studying the medicinal uses of a fungus found on wheat and other grains at the Sandoz pharmaceuticals firm in Basel.
He became the first human guinea pig of the drug when a tiny amount of the substance seeped onto his finger during a laboratory experiment on April 16, 1943.
"I had to leave work for home because I was suddenly hit by a sudden feeling of unease and mild dizziness," he subsequently wrote in a memo to company bosses.
"Everything I saw was distorted as in a warped mirror," he said, describing his bicycle ride home. "I had the impression I was rooted to the spot. But my assistant told me we were actually going very fast."
Upon reaching home, Hofmann began experiencing what he called "wonderful visions."
Three days later, Hofmann experimented with a larger dose. The result was the world's first scientifically documented bad trip.
"The substance which I wanted to experiment with took over me. I was filled with an overwhelming fear that I would go crazy. I was transported to a different world, a different time," Hofmann wrote.
Hofmann and his scientific colleagues hoped that LSD would make an important contribution to psychiatric research. The drug exaggerated inner problems and conflicts and thus it was hoped that it might be used to recognize and treat mental illnesses like schizophrenia.
For a time, Sandoz sold LSD 25 under the name Delysid, encouraging doctors to try it themselves. It was one of the strongest drugs in medicine -- with just one gram enough to drug an estimated 10,000 to 20,000 people for 12 hours.
LSD was elevated to international fame in the late 1950s and 1960s thanks to Harvard professor Timothy Leary who embraced the drug under the slogan "turn on, tune in, drop out."Hofmann died Tuesday at his home in Burg im Leimental, said Doris Stuker, a municipal clerk in the village near Basel where Hofmann moved following his retirement in 1971. To his dying day he enjoyed an occasional "trip." "Thinking is the best way to travel"