The single, produced by Mariah, Christopher "Tricky" Stewart, & James Wright, was sent to European radio stations on August 28th and official impacted U.S. radio on September 14, 2009.
Mick Jones said of her version: "I think she's actually retained the integrity of the song. You know, the arrangement is very similar to the original. They haven't tampered with the song too much. She's captured a certain emotional thing, a feeling."
Carey filmed a music video for "I Want to Know What Love Is" in September 2009 in New York City, directed by Hype Williams.
The video premiered on Mariah's official website on November 13, 2009. The video features Carey singing in Yankee Stadium, intercut with shots of audience members, often accompanied by loved ones, and some glimpses into the tough times in their past, as they grow emotional from the song's performance. A gospel choir joins Carey at the center of the stadium at the video's end. Carey wears the signature curly hairstyle from the initial stages of her career circa 1990–1993, maintaining the Memoirs theme of the album.
The single was generally well received by critics; Australian magazine Rhyme & Reason stated that "[While Carey stayed] [...] true to the original, this piano-led remake is less an overhaul of the classic '80s hit than it is a modest but impressive update." The UK Daily Star gave it a 5 out of 5 rating: "[The song is] given the Carey treatment and [is] complete with choir and karaoke climax. It's a great rework."
Bill Lamb from About.com said that: "Mariah Carey's new version could leave you speechless. The diversity of vocal coloring expressed in this recording is stunning. While the single Obsessed remains disappointing, this single is a reminder of just how formidable Carey's talents are given a strong production and arrangement."
Los Angeles Times said "[T]ackling a well-known power ballad seems like a safe choice. It's a comfortable fall-back plan after "Obsessed" performed well, but did far from blockbuster numbers. It will undoubtedly be a hit, but it's giving me more reason to fear Imperfect Angel. The sort-of-real/sort-of-not feud with Eminem seemed largely a ploy to keep Carey in the headlines, and covering Foreigner seems just as calculated to steer Carey back onto familiar ground." Entertainment Weekly said: "Mariah + Gospel Choir + "I Want to Know What Love Is" = Ecstasy."
Carey debuted "I Want to Know What Love Is" at her Live At The Pearl concerts in the Pearl Arena at The Palms Casino & Resport, Las Vegas, on September 11 and 12, 2009. Carey performed the song live on The Oprah Winfrey Show on September 18.
Carey taped a performance of the song in front of The View's studio audience on September 28 for an episode aired on October 2. On October 2, Carey performed the song live on The Today Show.
A New York radio station contest featured as its prize a mini concert by Carey at the P.C. Richard Theater in TriBeCa, New York on October 5, where she sang the song as well as "Obsessed" and "H.A.T.E.U.", also from the album.
During an international promotional trip, Carey taped an appearance performing the song on the television show Sketchbook in South Korea on October 13, for an episode to air on October 23. Carey performed the song in Japan on the television show Music Station on October 16.
Carey performed the single on Italy's X factor on November 11, and in France where she did various radio interviews.
The Mariah Carey: T4 Special aired in the UK featuring an interview and a performance on November 14. On November 19 she was interviewed and performed on the first show of the second series of Alan Carr's Chatty Man and switched on the Christmas lights at the Westfield London shopping center. Carey performed the song on The X Factor on November 22, GMTV on the 23rd and This Morning on the 24th.
The song peaked on the US Billboard Adult Contemporary chart at number ten, bringing Carey's total number of Top Ten hits on that chart to 20, one short of Celine Dion's record. She has since surpassed this and is now tied with Celine Dion after her single, "Oh Santa!" reached #1 in 2010.
However, on the U.S. Hot 100, it peaked at #60. On the UK Singles Chart, the song debuted at #19 on the week ending November 29, becoming her highest debuting and peaking song since 2008's "Touch My Body" which peaked at #5.
The song debuted at #6 in France, selling 1,910 physical CDs in its first week and 39,720copies of all formats there as of late 2009 becomes the best charting version of this song there. It placed 93rd on the Year-End Chart. It also reached #3 in Japan.
In Brazil, the song stayed at #1 for a record 27 weeks. The album is pending Platinum certification for shipments of over 60,000 copies, though it has been certified Gold. One of the reasons for the song's radio success there was its frequent inclusion in a popular new soap opera, "Viver a Vida."
According to Crowley Broadcast Analysis, Carey's version has broken the record for longest Brazilian Hot 100 Airplay Chart run at 27 consecutive weeks.