April 16, 1943 - Albert Hofmann unintentionally feels the first effects of his synthesis, LSD-25. Hofmann was working at Sandoz Pharmaceuticals working on synthesizing derivatives of lysergic acid. His 25th synthesis, which was first synthesized on November 16, 1938, did not seem to have too much therapeutic value, but he could not stop thinking about it. He decided to revisit this synthesis on April 16, 1943. During the process, he began feeling dizzy. Hofmann was unsure why he was feeling way because he always worked in the lab with such safety. He hypothesized that the chemical may have accidentally been absorbed through his skin at some point. Hofmann had to leave his lab on this day because of the following symptoms.. It would not be until a few days later (April 19, 1943) that Hofmann would experience the pure potency and power of LSD - also known as Bicycle Day.