In 1944, Fulton concluded, "Modern medicine considers its sleep producing qualities a superstition, its therapeutic action doubtful or nil." Another study of the time identified active bitter principles lactucin and lactucopicrin, but noted that these compounds from the fresh latex were unstable and did not remain in commercial preparations of lactucarium. Accordingly, lettuce opium fell from favor, until publications of the hippie movement began to promote it in the mid-1970s as a legal drug producing euphoria, sometimes compounded with catnip or damiana.[7][unreliable source?]