Bicycle Day Date in the current year: April 19, 2024

Albert Hofmann first synthesized lysergic acid diethylamide (LSD) in November 1938, while researching lysergic acid derivatives. The main intention of the synthesis was to obtain an analeptic (a central nervous system stimulant).

Five years later, Hofmann decided to re-synthesize LSD and take a second look at it. Having accidentally absorbed a small amount of LSD through his fingertips, he discovered its effects. On April 19, 1943, Hofmann intentionally took LSD and experienced intense changes in perception.

The events of his trip made Hofmann realize that he had discovered an extraordinary potent psychoactive substance. However, he did not think that anyone would use it as a recreational drug. He foresaw LSD as a psychiatric tool.

The anniversary of his LSD trip is known in psychedelic communities as Bicycle Day because Hofmann had to take a bicycle ride home from his laboratory. The first celebration took place in 1985. It was initiated by Thomas B. Roberts of DeKalb, Illinois.