Although our knowledge of hallucinogens is expanding rapidly, hallucino. genic agents have been used by man to produce mystical experiences for thousands of years. The plants and their extracts from which many of the natural drugs are derived are used both separately and in combinations. When used in combination, there is reason to believe that they might potentiate one another.' How the use of these drugs was discovered, how their appropriate dosages and proper combination were derived, is a fascinating area of investigation. Even if we do not now understand how "Dawn Age Psychopharmacologists" came to their conclusions, we know that they did. Today modern-day alchemists are interested in drugs which augment the hallucinogens to produce the "golden drug experience." We are also interested in treating bad trips, producing models of psychosis, as well as being just curious about how things work. Here we explore some of what is known about interactions of hallucinogens with drugs which might be used in treating "bad trips." We also examine the interactions of hallucinogens with themselves (tolerance and cross tolerance).