The "sweat" (exudate) is obtained from the skin of a large tree frog (Phyllomedusa bicolor).  During the process, no harm is done to the frog which afterwards is released unharmed.  The use of this poison frog emetic is not unique to the Matsés, and it is also commonly used by the Matis and Marubo Indians.  Moreover, its use by the Ticuna Indians was documented and published by anthropologists over fifty years ago.