Bicycle Day is an unofficial holiday celebrated annually on April 19th. It commemorates the day in 1943 when Swiss chemist Albert Hofmann intentionally ingested LSD (lysergic acid diethylamide) for the first time and embarked on a historic bicycle ride home from his laboratory. This ride, taken while under the influence of LSD, is famously known as the first intentional acid trip.

Hofmann had synthesized LSD five years earlier while researching lysergic acid derivatives for pharmaceutical company Sandoz Laboratories. He accidentally ingested a small amount of the compound on April 16, 1943, experiencing unusual sensations. Curious about its effects, Hofmann intentionally ingested a larger dose three days later, resulting in the now-famous Bicycle Day trip.

During his bicycle ride home, Hofmann experienced vivid hallucinations, altered perceptions of reality, and intense introspection. Despite initially feeling overwhelmed by the effects of the drug, Hofmann ultimately concluded that LSD had profound therapeutic potential. His experiences played a crucial role in popularizing LSD and kickstarting research into its potential uses in psychiatry, psychology, and spirituality.

Today, Bicycle Day is celebrated by psychedelic enthusiasts, researchers, and advocates as a day to reflect on the history and significance of LSD, as well as to promote awareness of the therapeutic potential of psychedelic substances. It serves as a reminder of the importance of responsible and informed use of psychedelics, as well as the need for continued research into their effects and potential benefits.