"Ayahuasca is a psychedelic decoction made from plants native to the Amazon Basin—most often Banisteriopsis caapi and Psychotria viridis—and which contains harmala alkaloids and N,Ndimethyltryptamine (DMT), the latter being a controlled substance scheduled under the 1971 Convention on Psychotropic Substances."

Source

Anderson, B. T.; Labate, B. C.; Meyer, M.; Tupper, K. W.; Barbosa, P. C. R.; Grob, C. S.; Dawson, A. & McKenna, D., "Statement on ayahuasca," International Journal of Drug Policy (London, United Kingdom: International Harm Reduction Association, March 2012), Vol. 23, No. 2.