Many have claimed enlightenment from drugs over time. I believe the drugs may have opened a new door onto reality for them, but that true enlightenment is a journey, not a single experience.

Tim Leary
Humphrey Osmond
Aldous Huxley
Abbie Hoffman
and many others . .

All saw/see LSD as a mind-opening pathway, a catalyst for enlightening experiences, and I believe they are right.

P.S. We are ignoring also millenia worth of shamans, medicine men, etc., who have used peyote/mushrooms/etc to experience 'visions' to help guide them on their life journey.