Email from Mr. Willem Scholten of the World Health Organization to Beatriz Labate regarding the health status of ayahuasca No plants (natural materials) containing DMT are at present controlled under the 1971 Convention on Psychotropic Substances. Consequently, preparations (e.g. decoctions) made of these plants, including ayahuasca are not under international control and, therefore, not subject to any of the articles of the 1971 Convention. Governments may have chosen to apply national control measures to ayahuasca that are more stringent than those required under the international drug control treaties, if such measures are desirable or necessary for the protection of the public health and welfare.