U.S. Supreme Court Case

Ayahuasca (EYE-ah-WAS-ka) or hoasca (Was-ka) is a psychoactive brew that contains the naturally-occurring compound, dimethyltryptamine (DMT). The brew iscustomarily prepared by combining bark scraped from the stem of Banisteriopsi caapi vine with leaves from the Psychotria viridis bush. These ingredients are boiled for several hours into a thick, brown liquid.

Photo courtesy of Maniti Camp Expeditions (Manitiexpedions.org).

Ayahuasca is used as a ceremonial sacrament by several South American religious groups. The U.S. Government challenged the religious use of hoasca after a Federal District Court granted a small Christian spiritualist church in New Mexico (UDV) the right to continue using their “tea.” A series of legal maneuvers landed the case in the U.S. Supreme Court [Alberto R. Gonzales v. O Centro Espirita Beneficiente Uniao Do Vegetal, No. 04-1084] which heard oral arguments on November 1, 2005. One issue raised by the case is the potential health risk of hoasca. I organized a group of scientists to file an Amicus Brief with the Supreme Court in support of the church.  The brief dealt exclusively with the health issues. A PDF file of that brief is available here: Amicus Brief. We strickly limited ourselves to the material in a Joint Appendix to which the parties had agreed. Thus we could not add medical and scientific research references that exist outside the Joint Appendix. …But there was plenty of excellent material in the Appendix that ran more than 1000 pages!

The photo above shows ayahuasca brew preparation by a legally recognized Brazilian church.

On February 21, 2006, the Supreme Court issued a unanimous opinion, written by Chief Justice Roberts, that read, in part: “it is true, of course, the Schedule I substances such as DMT are exceptionally dangerous. See, e.g., Touby v. United States, 500 U.S. 160, 162 (1991). Nevertheless, there is no indication that Congress, in classifying DMT, considered the harms posed by the particular use at issue here–the circumscribed, sacramental use of hoasca by the UDV.” [546 U.S. 418 (2006)].

There were other critical legal issues in this case, including the Government’s burden to show a compelling interest in prohibiting DMT use under the Religious Freedom Restoration Act. The Supreme Court’s ruling applies to the Government’s burden at the stage of a preliminary injunction, so it is possible the the issue of health risks from sacramental use of DMT will surface again in a trial on the merits.


The following three photos are from the appendix of doctoral dissertation in anthropology at the University of Wisconsin-Madison by Evgenia Fotiou, titled From Medicine Men to Day Trippers: Shamanic Tourism in Iquitos, Peru.  They show two shaman and a room used for ceremonies (includes two necessary toilets in the back).


I attempted to summarize the primary physiological and psychological risks from ayahuasca in an article that appeared in 2007 (vol. 102, pp. 24-24) in the journal Addiction. A PDF of the article can be retrieved here. Ayahuasca toxicity.