Writer, phytochemist, and ethnopharmacognosist (a word coined to describe his own profession). He currently dedicates himself to literature; he has written thirteen books, including: Pharmacotheon: Entheogenic Drugs, Their Botanical Sources and Their History [1993, 1996]; Análogos de la ayahuasca: enteógenos pangeicos [1994, 1995, 2006]; Pharmacophilia, o los paraísos naturales [1997, 1998]; Shamanic Snuffs or Entheogenic Errhines [2001; with the forthcoming edition of a Spanish version]; and Coca und Kokain [in German, with Christian Rätsch, 2003; partial versions in Spanish and English forthcoming]. His most recent book (and second literary work) is Mute Words. Silent Spectres of Speech / Sigil–Skeletons of Sound: The Ecstasy of Speech (still unpublished: it will eventually be written in Spanish as well; soon to be published in both languages). He is working on (a second volume for Pharmacophilia): Pharmacomania, or Mr. Jekyll and Dr. Hyde: The literary creation of "addicts" and "alcoholics" (which will be released soon in Spanish and English: the former as part of a series of his books in deluxe editions). He also plans to publish seven titles (both in Spanish and English) as ebooks.