Celebrating The 80th Anniversary Of Bicycle Day: A Different Kind Of Trip

No, it's not a holiday dedicated to two-wheeled, pedal-powered travel.

Laura Simmons - Editor and Staff Writer

Laura Simmons

Laura Simmons - Editor and Staff Writer

Laura Simmons

Editor and Staff Writer

Laura is an editor and staff writer at IFLScience. She obtained her Master's in Experimental Neuroscience from Imperial College London.

Editor and Staff Writer

black outline of a pushbike on a psychedelic colorful background

It was 80 years ago today that Albert Hofmann took a bike ride like no other. Image credit: hydracaput/

Every year, on April 19, an important anniversary rolls around that you may never have heard of. To those in the know, it’s called Bicycle Day, and it commemorates the first-ever intentional LSD trip. 

It all started when a Swiss chemist called Albert Hofmann had a very peculiar time while cycling home from the lab. Hofmann was the first person to synthesize LSD back in 1938. He did it by isolating chemical compounds found in a fungus called ergot, which infects grasses like rye and can have some profound effects on any humans unfortunate enough to accidentally consume it.


It’s safe to say that Hofmann didn’t think much of his discovery to begin with. What we now know as LSD was actually the 25th in a long line of similar compounds that he’d been experimenting with, and Hofmann’s research notes from the time reportedly reveal how no one was particularly enthused by it: “The new substance, however, aroused no special interest in our pharmacologists and physicians; testing was therefore discontinued.”

Albert Hofmann photographed in 1993
Albert Hofmann, pictured here in 1993, is often called the "Father of LSD". Image credit: Philip H. Bailey via Wikimedia Commons (CC BY-SA 2.5)

Five years later, though, in 1943, Hofmann turned his attention back to LSD. As the story goes, he was intrigued by the strange sensations he had felt when he had accidentally absorbed some of the compound through his skin, so much so that a few days later he decided to ingest some deliberately. It was only 0.25 milligrams, but it was more than enough.

It wasn’t long before the sensations brought on by the drug began to overwhelm Hofmann and he decided to head home. Unfortunately, since this was during the Second World War, the only means of transport available was a bike, and the journey was about 4 kilometers (2.5 miles). So began the first-ever acid trip – in both senses of the word.

“I had to struggle to speak intelligibly. I asked my laboratory assistant, who was informed of the self-experiment, to escort me home [...] 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,” wrote Hofmann, describing his experiences decades later in his autobiography LSD: My Problem Child. “I also had the sensation of being unable to move from the spot. Nevertheless, my assistant later told me that we had traveled very rapidly."


The hallucinations only got stronger when he arrived home. “Everything in the room spun around, and the familiar objects and pieces of furniture assumed grotesque, threatening forms. They were in continuous motion, animated, as if driven by an inner restlessness.”

In the midst of his trip, Hofmann was visited by a neighbor bringing him milk, which he had specifically requested and chugged with abandon, despite the fact that said neighbor appeared to him as a “malevolent, insidious witch with a colored mask.”

The remainder of the trip is described vividly in the book, including a visit by the family doctor. It all sounds quite unsettling – but in his own words, Hofmann awoke the next morning feeling pretty darn great: “The world was as if newly created. All my senses vibrated in a condition of highest sensitivity, which persisted for the entire day.”

Hofmann continued his research into LSD, and later other psychedelics like psilocybin. He believed that hallucinogenic drugs could be of benefit to patients with psychiatric disorders like schizophrenia, a view he maintained even when widespread recreational use of these drugs in the 1960s led to pushback from some quarters and eventual prohibition in law.


“I believe that if people would learn to use LSD's vision-inducing capability more wisely, under suitable conditions, in medical practice and in conjunction with meditation, then in the future this problem child could become a wonder child,” he wrote.

Hofmann died in 2008 at the age of 102. Nowadays, more and more researchers are taking a fresh look at the potential medicinal benefits of psychedelic drugs, and there have even been moves toward decriminalization in some areas. We can only guess that Hofmann would have been pleased to see his discovery becoming a topic of serious scientific research once again.

Of course, we can continue to mark our calendars each April 19th as the anniversary of a truly cycle-delic event that changed the world forever.


  • tag
  • psychology,

  • psychedelic drugs,

  • drugs,

  • hallucinogens,

  • LSD,

  • history of science,

  • trip