Tsentsak are invisible pathogenic projectiles or magical darts utilized in indigenous and mestizo shamanic practices for the purposes of sorcery and healing throughout much of the Amazon Basin. Anthropologists identify them as objects referenced in emic accounts that represent indigenous beliefs. Tsentak are not recognized in scientific medicine.

The term tsentsak is derived from the Shuar language, which belongs to the Jivaroan language family. The Shuar are members of the Jivaroan peoples who reside in the Amazon rainforest of Peru and Ecuador. This term is also used interchangeably with virote (primarily by mestizo shamans), a Spanish term for crossbow bolt which was applied to the blow darts made by the Jivaroans from the spines of the Bactris and Astrocaryum palms.

Tsentsak are stored by the shaman in his or her yachay, or phlegm, located in the chest and stomach. The tsentsak are embedded within this phlegm and either the tsentsak or the yachay may be projected out of the shaman into a victim to cause illness and death. This phlegm is the materialization of the shaman's power; it is used to remove tsentsak from the bodies of victims as well as to protect the shaman from being harmed by the tsentsak of others.

Tsentsak are only visible under the influence of a psychoactive substance called natemä, which is the Jívaro word for ayahuasca. When the shaman imbibes natemä, the world of spirits becomes visible. It is at this time that sorcerers and bewitching shamans can send tsentsak to their victims, while conversely, healers and curing shamans can remove tsentsak from their afflicted patients.

Tsentsak are believed to possess their own agency and volition as living spirits that constantly desire to kill and consume human flesh. A shaman must learn to control their darts lest they escape and cause unintended harm. To facilitate control of tsentsak they must be nourished by the consumption of mapacho (Nicotiana rustica), which can be smoked or imbibed as an infusion.

A shaman who does not possess the necessary restraint to swallow their tsentsak when they rise to the back of their throat will become a sorcerer or bewitching shaman, while a shaman who can learn to control these urges will become a healer or curing shaman.

An apprentice shaman who receives their first tsentsak from a predominantly bewitching shaman is likely to become a sorcerer, while the apprentice that receives their first tsentsak from a curing shaman will most likely become a healer.

Throughout much of the Amazon, tsentsak are believed to be the primary cause of illness and nonviolent death. These magical darts are utilized by brujos, (shamans specializing in attack sorcery) to bring suffering and death to their victims. The darts can be regurgitated at will by the sorcerer and projected from the mouth into the body of the victim. If the dart passes entirely though the victim they will die in three to seven days, however, if the dart becomes lodged in the victim's body, it may be removed by a curing shaman.