By [Alexander] Shulgin's own count, he has created nearly 200 psychedelic compounds, among them stimulants, depressants, aphrodisiacs, ''empathogens,'' [and] convulsants. And in 1976, Shulgin fished an obscure chemical called MDMA out of the depths of the chemical literature and introduced it to the wider world, where it came to be known as Ecstasy. Most of the scientific community considers Shulgin at best a curiosity and at worst a menace. Now, however, near the end of his career, his faith in the potential of psychedelics has at least a chance at vindication. A little more than a month ago, the [FDA] approved a Harvard Medical School study looking at whether MDMA can alleviate the fear and anxiety of terminal cancer patients. And next month will mark a year since [the start of a] study of Ecstasy-assisted therapy for post-traumatic stress disorder. Shulgin's knack for befriending the right people hasn't hurt. A week after I visited him, he was headed to Sonoma County for the annual ''summer encampment'' of the Bohemian Club, an exclusive, secretive San Francisco-based men's club that has counted every Republican president since Herbert Hoover among its members. For a long time, though, Shulgin's most helpful relationship was with the D.E.A. itself. The head of the D.E.A.'s Western Laboratory, Bob Sager, was one of his closest friends. In his office, Shulgin has several plaques awarded to him by the agency for his service. Shulgin has been credited with jump-starting today's therapeutic research.