Drug discussed in Aldous Huxley's "Heaven and Hell"

LSD

This psychedelic compound was first synthesized in 1938 and later explored for its mind-altering effects in the 1950s and 60s. Huxley described its effects as opening "the doors of perception."

Aldous Huxley’s 1956 essay Heaven and Hell explores mind-altering substances, including mescaline, but it also references LSD—a powerful hallucinogen that later became iconic in 1960s counterculture. The clue points to LSD because Huxley discussed its potential to induce mystical experiences, though he focused more on mescaline in his earlier work The Doors of Perception. Since LSD fits the letter count and ties directly to the book’s themes, it’s the intended answer.