Bicycle Day: The Trip that Changed Psychedelic History

Even though Bicycle Day involved an actual trip on a bicycle, it was another kind of “trip” that would get this day into the history books. Bicycle Day is a celebration that commemorates the day Albert Hofmann first tripped on LSD, and bicycled home from his lab in Basel on April 19, 1943.

Lysergic acid diethylamide (LSD), also known as acid, was first synthesized on November 16, 1938 by Swiss scientist Albert Hofmann in the Sandoz laboratories in Basel, Switzerland. The main reason behind the synthesis was to obtain a respiratory and circulatory stimulant. Bicycle Day was born five years later on April 19, 1943, when the father of psychedelic medicine discovered the power of LSD.

This wasn’t the Swiss chemist’s first encounter with the effects of LSD as he was accidentally exposed to a small dose on April 16, 1943. Hofmann described what he felt on that day as 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 about two hours this condition faded away.”

Three days later, Hofmann was determined to actually experience the true power of LSD, ingesting a 250 microgram dose, an amount he predicted to be a threshold dose (an actual threshold dose is 20 micrograms). About 40 minutes after the dose, he wrote the one and only entry in his lab journal:

17:00: Beginning dizziness, feeling of anxiety, visual distortions, symptoms of paralysis, desire to laugh.

“I was able to write the last words only with great effort,” he wrote in his book, LSD: My Problem Child. “I had to struggle to speak intelligibly.”

Hofmann asked his assistant to escort him home. As was customary in Basel at that time due to wartime restrictions, the two made the journey by bicycle. On the way home, Hofmann’s condition deteriorated rapidly as he struggled with feelings of anxiety, while believing his next-door neighbor was an evil witch, that he was going insane, and that LSD had poisoned him.

On his experience during the ride back on Bicycle Day, Hofmann is quoted saying: