|As of yet, we know of no published source rounding up and documenting the use of entheogens -- including cannabis -- by well-known figures; only mentions throughout various articles and books.|
Notwithstanding exceptions like Mullis, it is far easier to document a person's use of entheogens once they've passed away. For example, after Carl Sagan's death in 1996 it came out that the personal account by "Mr. X" in Lester Grinspoon's book, Marihuana Reconsidered (1971), was actually written by Sagan. He wrote the account in 1969 when he was in his mid-30s. He continued to use cannabis for the rest of his life.
Other people's use can often be confirmed but it's an imprecise science. The Fitz Hugh Ludlow Memorial Library and the Schaffer Psychedelic Library are two places to look for mentions of historial figures. Otherwise we're keeping our ears to the ground on this question.
There are a few compiled lists around such as the one below :
Famous Drug Users
I think I might have been stupid, in some respects, if it weren't for my psychedelic experiences.
- Kary Mullis, Ph.D., Nobel Prize Laureate, Chemistry, 1993