What is "Bicycle Day"?

On April 19th 1943 Albert Hoffman famously took his first intentional dose of lysergic acid diethylamide (LSD), which he had accidentally synthesised 5 years beforehand whilst trying to create a respiratory and circulatory stimulant (analeptic).

After first synthesising LSD in November 1938, Hoffman had an insight that he should not discard the compound and so it was set aside. Five years later, on 16th April 1943, he chose to reexamine what he had created. In doing so, he accidentally ingested some of the LSD via his fingernails and had his first trip. He descried the experience as a “not unpleasant intoxicated-like condition” and said that he "perceived an uninterrupted stream of fantastic pictures, extraordinary shapes with intense, kaleidoscopic play of colours" (sound familiar?).

Three days later, on April 19th 1943, Hoffman decided to take an intentional dose of this novel and mind bending creation (250 micrograms, no less!). The "bicycle” part of this day references the fact that Hoffman took his intentional dose before getting on his bike and cycling home - you can read more about this trip below.

Hoffman called LSD a “sacred drug”. He intuitively knew it could help people and dedicated much of his time to this cause. Little did he know at the time that his “mistake” would change the lives of so many people.

Hoffman's Bicycle Day Trip Report (in full)

"19/4/43 16:20: 0.5 cc of 1/2 promil aqueous solution of diethylamide tartrate orally=0.25mg tartrate. Taken diluted with about 10 cc water. Tasteless.

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

Supplement of 4/21: Home by bicycle. From 18:00 - ca.20:00 most severe crisis. (See special report)"

"Here the notes in my laboratory journal cease. I was able to write the last words only with great effort. By now it was already clear to me that LSD had been the cause of the remarkable experience of the previous Friday, for the altered perceptions were of the same type as before, only much more intense. I had to struggle to speak intelligibly. I asked my laboratory assistant, who was informed of the self-experiment, to escort me home. We went by bicycle, no automobile available because of wartime restrictions on their use. On the way home, my condition began to assume threatening forms. Everything in my field of vision wavered and was distorted as if seen in a curved mirror. I also had the sensation of being unable to move from the spot. Nevertheless, my assistant later told me that we had travelled very rapidly. Finally, we arrived at home safe and sound, and I was just barely capable of asking my companion to summon our family doctor and request milk from the neighbors.