Practically unknown in the Western countries a few decades ago, ayahuasca and its rituals are actually making a remarkable entry in them. A multi- and interdisciplinary review of this peculiar psychotropic preparation, of which two of the major alkaloids are naturally present in the human body, is presented. The biochemical (compositions), pharmacological (modes of action), and biomedical (cardiovascular parameters, EEG, acute and long term risks, therapeutic utility) aspects particularly retained our attention. A neuropharmacological hypothesis concerning the documented « anti-addictive » potential of ayahuasca is indicated. Expressible in terms of harm limitation, reasons to avoid the – often more reflex than carefully thought-out – pathologization and prohibition are exposed. In conclusion is emphasized the necessity to also orient research on the links between the explicit requests addressed to ayahuasca (complementary and alternative therapies, personal achievement, spiritual initiation and development) and the answers brought by ayahuasca rituals.