Ayahuasca is used largely as a religious sacrament. Those whose usage of ayahuasca is performed in non-traditional contexts often align themselves with the philosophies and cosmologies associated with ayahuasca shamanism, as practiced among indigenous peoples like the Urarina of Peruvian Amazonia. The religion Santo Daime uses it.
While non-native users know of the spiritual applications of ayahuasca, a less well-known traditional usage focuses on the medicinal properties of ayahuasca. Its purgative properties are highly important (many refer to it as la purga, "the purge"). The intense vomiting and occasional diarrhea it induces can clear the body of worms and other tropical parasites, and harmala alkaloids themselves have been shown to be anthelmintic Thus, this action is twofold; a direct action on the parasites by these harmala alkaloids (particularly harmine in ayahuasca) works to kill the parasites, and parasites are expelled through the increased intestinal motility that is caused by these alkaloids.
Dietary taboos are almost always associated with the use of Ayahuasca; in the rainforest, these tend towards the purification of one's self - abstaining from spicy and heavily seasoned foods, fat, salt, caffeine, acidic foods (such as citrus) and sex before, after, or both before and after a ceremony. A diet low in foods containing tyramine has been recommended, as the speculative interaction of tyramine and MAOIs could lead to a hypertensive crisis. However, evidence indicates that harmala alkaloids act only on MAO-A, in a reversible way similar to moclobemide (an antidepressive that does not require dietary restrictions). Psychonautic experiments and absence of diet restrictions in the highly urban Brazilian ayahuasca church União do Vegetal also suggest that the risk is much lower than conceived, and probably non-existent.
Today, the name 'ayahuasca' can mean a variety of botanical concoctions containing one or more MAOIs and DMT or one of its chemical analogues. The synthetic pharmahuasca is sometimes called ayahuasca as well. In this usage, the DMT is generally considered the main psychoactive active ingredient, while the MAOI merely preserves the psychoactivity of orally ingested DMT, which would otherwise be destroyed in the gut before it could be absorbed in the body. Most ayahuasqueros and others working with the brew claim the B. caapi vine to be the defining ingredient; according to them, it is not ayahuasca unless B. caapi is in the brew. The vine is considered to be the "spirit" of ayahuasca, the gatekeeper and guide to the otherworldly realms.
In some areas, it is even said that the chakruna or chaliponga admixtures are added only to make the brew taste sweeter. This is a strong indicator of the often wildly divergent intentions and cultural differences between the native ayahuasca-using cultures and psychedelics enthusiasts in other countries.
In modern Europe and North America, ayahuasca analogues are often prepared using non-traditional plants which contain the same alkaloids. For example, seeds of the Syrian rue plant are often used as a substitute for the ayawaska vine, and the DMT-rich Mimosa hostilis is used in place of chakruna. Australia has several indigenous plants which are popular among modern ayahuasqueros there, such as various DMT-rich species of Acacia.