[1] It achieved mainstream success by Colombian singer-songwriter Shakira, who recorded a cover taken from her ninth studio album, Sale el Sol (2010).

It was written and produced by Shakira, with additional songwriting from Edward Bello, Armando Pérez, and Dylan Mills.

The song is a Latin pop and merengue track that lyrically describes Shakira's eccentric infatuation with a man.

The English version of the song became a worldwide commercial success and peaked inside the top five of the record charts of countries including Austria, Belgium, France, Hungary, and Italy.

[2] The album marked the first time she worked with Bello, who is better known by his stage name El Cata, and their collaboration started after Shakira expressed her desire to experiment with merengue music, saying "I grew up listening to merengue— that was a big part of my life, and I was missing it".

[3] Merengue is a type of music and dance originating in the Dominican Republic, and after being referred to Bello by Pitbull, Shakira travelled to the country and began recording sessions with him in his "tiny" studio in Santo Domingo.

"[7] In an interview with Billboard, Dizzee Rascal said about Shakira that, "she's a bit of a trendsetter -- she does loads of different things on a major scale" and added "You'd expect her to use an American rapper [for the song], but she chose me.

[10] On 19 August 2014, Alvin Hellerstein, senior judge of the U.S. District Court for the Southern District of New York, concluded that the Spanish version of "Loca" had been indirectly plagiarised from "Loca con su Tiguere", a mid-1990s song composed by Dominican songwriter Ramon "Arias" Vasquez.

As the Spanish version of "Loca" features Bello singing numerous portions, the judge reasoned that it too was plagiarised from Vasquez's song.

After a trial phase, SonyATV Latin and Sony/ATV Discos (the distributors of the Spanish version of "Loca" in the United States) will pay damages to Mayimba Music, the owner of the rights to Vasquez's song and the plaintiff in the lawsuit.

[11] On 10 August 2015, the case was dismissed by Hellerstein after Sony Music brought forth new evidence suggesting that Vasquez had fabricated the cassette tape that he had earlier produced in court to prove that the song was originally recorded by him.

Hellerstein said the evidence given by Sony Music provided "competent and substantial proof" that the cassette tape was fake.

A reviewer from Billboard complimented Shakira for displaying her unpredictable musical choices by having Dizzee Rascal sing over a merengue beat, which they termed as a "jarring combination".

[15] James Reed from The Boston Globe termed it as an "irresistible merengue hybrid" and deemed the Spanish version of the song as an album essential.

[16] Michelle Morgante, again from The Boston Globe, was impressed by the song's effectiveness in both its Spanish and English version, which she commented is "lost in some of Shakira's other attempts at language switching".

[23] The English version of the song received a nomination in the category of "Best Latin/Reggaeton Track" at the 26th Annual International Dance Music Awards in 2011.

After roaming about the city, including numerous scenes of dancing, she publicly changes her wardrobe and hitches a ride on a motorbike.

[65] Shakira performed the song with Dizzee Rascal together for the first time on the MTV Europe Music Awards 2010 on 7 November.

[66] Gabi Gregg from MTV chose the performance as the best on the show, praising Shakira's dance moves and noting that "she actually sounds the same live as she does recorded".

[67] Jillian Mapes from Billboard included the performance on her list of "5 Must-See Moments at the 2010 MTV European Music Awards".

[70][71] On 25 October 2010, Shakira was leaving the Honda Centre parking lot in California after a concert, but got out of her limo and performed "Loca" with two dancers on top of a car.