solo and duet versions of "Nobody Wants to Be Lonely" were written by Desmond Child, Victoria Shaw, and Gary Burr, while the production for the solo version was handled by Desmond Child and the duet's production was handled by Walter Afanasieff. Martin and Danny Lopez co-wrote "Sólo Quiero Amarte". According to the duet version's sheet music on Musicnotes.com, "Nobody Wants to Be Lonely" uses piano and guitar and is composed in the key of B♭ minor with a groove of 100 beats per minute. Martin and Aguilera's vocals span from the low note of D♭4 to the high note of D♭6. The album version track runs for a total of five minutes and five seconds, while the duet runs for a total of 4 minutes and 12 seconds. According to Stephen Daw from Billboard, "Nobody Wants to Be Lonely" is a love song about "heartbreak" and "longing", as well as "love, lose, and hope" according to mitú's Cristal Mesa, with lyrics including, "Nobody wants to be lonely / Nobody wants to cry / My body's longing to hold you / So bad, it hurts inside / Time is precious and it's slipping away / And I've been waiting for you all of my life". Critical reception "Nobody Wants to Be Lonely" has been met with widely positive reviews from music critics. Billboard staff reviewed the duet version, following its release in January 2001, writing that the song was "edgier and sexier" than Martin's previous works and calling his vocal performance with Aguilera "radiant". They described the track as "the combination of two of pop music's most sexually charged performers", mentioning the song's "sensuality" and its "feel-good vibe". British trade paper Music Week referred to the duet as a "pop swayer" and noted its "perfect" performance. AllMusic reviewer Jose F. Promis wrote that the duet version was more "bombastic" than the solo album version. The Los Angeles Times staff described the singers as "two of pop's hottest heartthrobs". Tangos Alice Kelly stated: "These two harmonize each other so beautifully that anyone would be convinced their love story was real." Writing for The Advocate, Gina Vivinetto praised "Nobody Wants to Be Lonely", saying the singers "blended their voices beautifully" on the track. Cristal Mesa from mitú described them as "two vocal powerhouses" and said they "definitely keep your attention as they sing" the song. In 2017, Bustle critic Mathew Jedeikin gave the