A side effect is an effect that is secondary to the one intended.
Side effect or side effects may also refer to:
Side effect (computer science), a state change caused by a function or expression Side effect (medicine), an unintended effect of the use of a drug
Media Side Effects (Allen book), a 1986 collection of short stories by Woody Allen Side Effects (TV series), a 1994 Canadian TV series "Side Effects" (Ben 10 episode), a 2006 episode of television series Ben 10 Side Effects (Bass book), a 2008 nonfiction book by Alison Bass
Film Side Effects (2005 film), starring Katherine Heigl Side Effects (2013 film), directed by Steven Soderbergh The Side Effect, a 2014 film directed by Ti West Side Effects, an Indian romcom film series, including Pyaar Ke Side Effects (2006) Shaadi Ke Side Effects (2014)
Music Bands Side Effect (band), a 1972–1982 American disco and jazz-funk band The Side Effects (band), a 1980–1982 American indie rock band
Albums Side Effect (album), by Side Effect, 1975 Side Effects (Dallas Smith album) or the title song (see below), 2016 The Side Effects (album), by Coldrain, or the title song, 2019 Side Effects (EP), by Mads Langer and Tim Christensen, or the title song, 2014 Side Effects, by White Denim, 2019
Songs "Side Effects" (The Chainsmokers song), 2018 "Side Effects" (Dallas Smith song), 2016 "Side Effects" (Mariah Carey song), 2008 "Side Effects", by Becky Hill from Believe Me Now?, 2024 "Side Effects", by Carlie Hanson, 2019 "Side Effects", by Mimi Webb from Confessions, 2025 "Side Effects", by Stray Kids from Clé 2: Yellow Wood, 2019 "Side Effects", by Ty Dolla Sign from Beach House 3, 2017
See also Side product Side reaction By-product Causality Unintended consequences