Each ingredient of Mentawai poison is harmless in and of itself. However, when juices from the tuba shrub, the ipoh tree and chili fruits are mixed together, the combination is deadly.

Mentawai men dip their arrows, tipped with sharpened palm leaf stems, in the poison prior to hunts. Chili juice increases the circulatory affects of the poison: an animal struck by a Mentawai arrow will die within thirty seconds. The death is quick, painless and humane: suffering is anathema to the Mentawai.

Four primates: Black Gibbon, Mentawai Macaque, Long-tailed Joja and Pig-Tailed Langur are endemic to Siberut. All species are hunted by Mentawai men. In the past, survival of the Pig-tailed Langur and the Bilou, both of which are highly vulnerable to hunters, was assured by taboos surrounding their killing. As these taboos disappear, and local hunting with airguns increases, the likelihood of extinction for these primates skyrockets.