The track is a down-tempo ballad that talks about an unfaithful man, who has left Aguilera's world "infected".
In the United States, the single reached number 20 on the Bubbling Under Hot 100 Singles, but topped the Hot Dance Club Play chart.
The song had moderate success in Belgium and Israel, peaking in the top twenty in both countries.
The music video for the song was directed by Anthony Mandler.
Written in the key of A minor, "You Lost Me" has a tempo of 50 beats per minute.