Lovato wrote the song along with Lindy Robbins and its producers Andrew Goldstein and Emanuel Kiriakou.
[1] "Warrior" peaked at number 25 on the Bubbling Under Hot 100 and was certified Gold by the Recording Industry Association of America (RIAA).
"[2] In a review of Demi, Jason Lipshutz of Billboard compared "Warrior" to Lovato's single "Skyscraper", stating that "Warrior" has Lovato declaring herself "a phoenix that has risen from all-too-public ashes", with emotional lyrics such as: "I've got shame, I've got scars, that I will never show/I'm a survivor, in more ways than you'll know".
In celebration of the release of the album, Demi, Lovato shared a picture of her shoulder tattoo with the phrase "now I'm a warrior", referencing the song's lyrics.
The song also reached the top 80 on iTunes at the time, achieving a new peak, since it was not released as a single.