Insanecide was a heavy metal and hard rock trio from Volta Redonda, Rio de Janeiro, Brazil, active from 2013 until their split-up. The band combined the rhythmic weight of groove metal with melodic hard rock sensibilities, drawing comparisons to Pantera, and released the four-track EP Counter alongside a music video for the track "The Rift."

Insanitears is a doom/black metal band from Teresina, Piauí, Brazil, active since around 2019. The band explores themes of death, judgment, witchcraft, and the occult within a dark, slow-burning sound rooted in the Brazilian underground metal scene.

Insanity was a death/thrash metal band from Fortaleza, Ceará, Brazil, formed in 1989 under the name HON (Hexistence of Noise) by bassist/vocalist George Frizzo and guitarist Alberto Lopes before adopting the Insanity name later that year. The band released the demo "In Search of Reason" in 1990, recorded at Proaudio Studios in Fortaleza, and later issued the full-length "Phobia" in 1993 through Muvuca Records before splitting up in 2003.

Insanity Seas is a doom/death/sludge metal project from Porto Alegre, Rio Grande do Sul, Brazil, conceived by Henrique and Love Streit and active since 2021. Drawing lyrical inspiration from the cosmic horror fiction of H.P. Lovecraft, the band channels oppressive, slow-grinding riffs into an atmosphere of dread rooted in Lovecraftian mythology.

Insanity Storm is a melodic black metal band from Concepción, Chile, founded in 2023 by Countess Elizafer (Nicole Molina), who recorded all instruments and vocals for the debut album Caos Destrucción, released in December 2023. The band expanded to a full lineup with drummer Count Salvatore (Esteban Medina) and released the eight-track EP Eternal Winter in February 2025, with a conceptual narrative centered on the character Lilith; their upcoming album Winterworn is set for release through Solistitium Records of Germany, the former home of Behemoth, Tsjuder, and Horna.

Insannica is a metal band from Juiz de Fora, Minas Gerais, Brazil, founded in late 2010 with roots in thrash metal and a sound that has since incorporated groove metal, metalcore, hardcore, and progressive influences. The band has released original material including the track "Mitopatia" via their Bandcamp page, reflecting their eclectic, genre-blending approach.

Insecticida is an old-school thrash metal band from Timbaúba, Pernambuco, Brazil, playing aggressive 1980s-style thrash with no modern frills. The band infuses northeastern Brazilian culture into their music, including humorous lyrics that tackle social themes with regional irony, and released their debut EP "Deu a Mulesta dos Cachorro" in 2017.

Insidious Nature is a progressive/technical death metal band from São Luís, Maranhão, Brazil, formed around 2020 by vocalist Pitter Cutrim, guitarists Rogers Rocha and Luke Hellstrvm, bassist Lucas Abreu, and drummer Lucas Mano. Citing Death, Cynic, and Beyond Creation as primary influences, the band released the single "Doomed Epilogue" in 2022 and their debut album "A Prelude to the Endless" in June 2023.

Insomnio Mutante is a thrash metal band from Chillán, Chile, active since 1998. They released their debut album Mundo Desconocido in May 2014, recorded at Estudios Decibeles between September 2013 and March 2014.