The powerful hallucinogenic brew ayahuasca is widely tipped to become a cornerstone of future mental healthcare practices, yet a new study on the adverse effects associated with the Amazonian concoction provides an important reminder as to the need to proceed with caution when dealing with such potent substances. Overall, researchers found that ayahuasca users commonly experience negative side effects, and while these are usually mild and short-lived, they tend to occur more frequently when the DMT-containing beverage is consumed outside of ceremonial contexts.
In their write-up, the study authors acknowledge that it is difficult to assess the safety of ayahuasca using the same criteria that are generally applied to more conventional medicines, since the primary psychoactive effects of all psychedelics are typically seen as undesirable by medical standards. For instance, any prescription medication that produces hallucinations is likely to be deemed unsafe, whereas altered states of consciousness are a fundamental component of psychedelic-assisted psychotherapy.
“In that sense, ayahuasca practices can hardly be assessed with the same parameters used for prescription medicines, since the myriad of its effects include challenging experiences that are intrinsic to the experience, some of which are considered as part of its healing process,” write the researchers.
In addition to its psychedelic effects, ayahuasca is also known to trigger an intense physical purge, often characterized by intense vomiting although users have also been known to poop themselves. Obviously, such messy outcomes are unlikely to be viewed as advantageous when assessing the safety profile of a prescription medication.
To determine the full scope of ayahuasca’s secondary effects, the study authors analyzed responses to the Global Ayahuasca Survey provided by 10,836 people from more than 50 countries. As expected, vomiting and nausea were the most frequent adverse physical health effects, and were reported by 68.2 percent of participants.
Headaches, which occurred in 17.8 percent of respondents, were the next most common physical complaint associated with ayahuasca.
Putting this finding into context, the researchers say “it is important to clarify that vomiting/nausea is considered a normal effect of ayahuasca for experienced users. In the case of traditional ayahuasca ceremonies and even in non-traditional ceremonies, not only is vomiting/nausea not considered an adverse effect, but it is even sought out for its purging and perceived spiritual cleansing benefits.”
Having said that, 2.3 percent of respondents reported that they had sought medical attention for physical adverse effects after drinking ayahuasca.
Negative mental health effects were also common, occurring in 55.4 percent of participants. However, more than half of these adverse events involved “hearing or seeing things that other people do not hear or see”, which is a normal consequence of ayahuasca use.
Furthermore, around 88 percent of respondents said that these uncomfortable hallucinations ultimately resulted in positive psychological transformations. On the other hand, however, roughly 12 percent sought professional help for ongoing negative mental health effects after drinking ayahuasca.
The study authors also stress that unsupervised use was linked to higher rates of negative side effects, and that “using ayahuasca in group and ceremonial settings, especially in a religious context, seemingly protects users from developing more adverse side effects.” In addition, they find that people with a history of trauma, substance use disorders, or neurological conditions are particularly likely to suffer if using ayahuasca without proper guidance or support.
Overall, they say that “while there is a high rate of adverse physical effects and challenging psychological effects from using ayahuasca, they are not generally severe, and most ayahuasca ceremony attendees continue to attend ceremonies, suggesting they perceive the benefits as outweighing any adverse effects.”
The study appears in the journal PLOS Global Public Health.