In 1982, Arévalo co-founded Aplicación de Medicina Tradicional (AMETRA), an organization that sought to improve the sustainability of health care for the Shipibo-Conibo people by integrating traditional plant medicines.

He worked with patients who were recovering from surgery;[4] some of them told him that the hospital's treatments didn't make them feel better, even if examinations and test results indicated improvement.

[3] Through observations and conversations with patients and hospital staff—especially a Swedish doctor named Anders Hansson—he concluded that Western medicine did not meet all the needs of the indigenous population.

[3] But the limits to the hospital's efficacy were not just a matter of cultural difference: The indigenous population was contending with serious health problems and constrained medical resources.

[6] In 1982, Arévalo and Anders Hansson co-founded a local organization called Aplicación de Medicina Tradicional (AMETRA), which (with Swedish funding) sought to revive the traditional medicine practices of Shipibo-Conibo people,[8] and to look for ways to incorporate them into a health system for indigenous communities.

[11][12] The practicality of an integrative medicine approach attracted the attention of two regional federations of indigenous peoples: FECONAU (Federacíon de Comunidades Nativas del Ucayali y Afluentes)[10] and FENAMAD (Federación Nativa del Río Madre de Dios y Afluentes), who sought to apply AMETRA's ideas to a revised health system in their own regions.

Arévalo expressed the view that traditional medicine is of pivotal importance to Amazonian cultures, and that indigenous communities must be able to negotiate access to it in order to prevent exploitation and environmental harm.

[2] Another of Arévalo's students, Ricardo Amaringo, opened a lodge called Nihue Rao (aka Ronin Saini) in 2011, in partnership with American family medicine practitioner Joe Tafur and Canadian artist Cvita Mamic.

[20][21][22][23] A central fixture at the retreat lodges is the administration of ayahuasca, a psychedelic tisane used and revered by ethnic groups throughout the Amazon Basin.

Jan Kounen, director of D'autres mondes, met Arévalo in the Peruvian Amazon while conducting research for his film Blueberry (2004).

[25][26][citation needed] Two songs sung by Arévalo (credited to his Shipibo name, Kestenbetsa) appear on the Blueberry soundtrack.