Other medicinal or visionary plants are typically added according to the formula of the presiding shaman, the purposes of the ceremony, or geographic locality. It is claimed to cure a wide range of physical, psychological, and spiritual maladies. Western scientists and traditional shamans classify different forms of ayahuasca according to botanical or functional characteristics. Western scientific studies are confirming beneficial medical and psychotherapeutic applications. The medicine is always properly consumed in a ceremonial setting which has been sanctified by sacred protective rituals called arcanas , the smoke of the sacred tobacco mapacho , the mysterious shamanic potion camalonga , and the scents of agua de florida, agua de kananga, and other perfumes deemed especially appealing to the spirits.
Vomiting is a fundamental aspect of the holistic purge and is almost inevitable.
Temporary diarrhea may also occur as the medicine cleanses the system. These effects are generally transient and experienced by most, but not all people partaking of La Medicina . The generally negative western attitude toward vomiting is a culturally biased viewpoint not absolute in any biomedical sense. It is not solely a manifestation of illness. In the shamanic culture of the Amazon, purging by vomiting and defecation is considered a positive and beneficial aspect of the cleansing process.