"Toxic" is a recorded song by American singer Britney Spears for her fourth studio album, In the Zone (2003). It was written and produced by Christian Karlsson and Pontus Winnberg (known collectively as Bloodshy & Avant), with additional writing from Cathy Dennis and Henrik Jonback. The song released on January 13, 2004, by Jive Records, as the second single from the album. After trying to choose between "(I Got That) Boom Boom" and "Outrageous" to be the second single from In the Zone, Spears selected "Toxic" instead. A dance-pop song with electropop influences, "Toxic" features varied instrumentation, such as drums, synthesizers and surf guitar. It is accompanied by high-pitched Bollywood strings and breathy vocals. Its lyrics draw an extended metaphor of a lover as a dangerous yet addictive drug. The song has received critical acclaim by music critics, who deemed it as the strongest track of In the Zone, while praising its hook and chorus.