Frog medicine, known in Spanish as Medicina del Sapo, originally know as Kambo in old Matses language; sometimes referred as kambô and Vacina do sapo in Brazilian portuguese, this ancient ceremony is performed by native experts from the Mayoruna tribe (Matsés people), and other indigenous people of the Amazon.
In the Matsés, the ceremony starts by catching a giant leaf frog (Phyllomedusa bicolor) also called giant monkey frog in English, because it climbs into the rainforest canopy. The Mayoruna expert immobilizes it by tying its four extremities, extracts the poison from its back with a small wooden stick and places it on a piece of cane, then release the frog. He subsequently dries and stores the stick to be used for this practice.
Later, before applying it, the expert rehydrates the dried poison with water or saliva. The expert heats up a thin piece of vine (tamshi) and burns several points on the participant’s arm or chest, producing instant blisters on his/her skin. The amount of burn marks will depend on the tolerance of each person. The blisters will then be scratched open one by one and the poison extracted from the frog will be applied on the wounds.
This practice is usually performed on rainy days by the Mayorunas in order to get more energy, trust and improve their shooting skills for hunting purposes. Several days after having been stung, the Mayorunas will go hunting and try their best shot with bow. 
According to researchs, the substance segregated by the giant leaf frog contains deltorphin, acting as an emetic and dermorphin, acting as a powerful analgesic. This practice is actually used as a treatment in alternative medicine.
An expedition to the Matses territories takes at least 2 weeks.