The album was re-released as Turn It Up Louder on 18 October 2010. It was preceded by the release of "Broken Arrow" as its lead single, and includes nine other bonus songs. In 2010, it was reported that Interscope Records was planning to release Turn It Up in the United States with new songs in early 2011, which never materialised.
"Mama Do (Uh Oh, Uh Oh)" was released digitally in the United Kingdom on 6 June 2009 and physically on 8 June as the album's lead single. It debuted at number one on the UK Singles Chart, making Lott the first British female solo artist to have a debut single enter atop the chart without previously appearing on a reality show.
Follow-up single "Boys and Girls" was released on 5 September 2009, a week before the album's release. The song debuted at number seventy-three on the UK Singles Chart before climbing to number one the following week, earning Lott her second consecutive chart-topper and breaking yet another record by becoming the biggest leap to the top position in the UK chart history.
"Cry Me Out", released as the third single on 30 November 2009, peaked at number twelve on the UK chart, Lott's first single to miss the number-one spot, as well as the top ten.
"Gravity" was released as the album's fourth single on 8 March 2010. It charted at number twenty in the UK, making it her fourth consecutive top twenty single.
"Turn It Up" was released as the fifth single on 7 June 2010, for which a music video, directed by Nick Frew, was shot in Los Angeles on 17 April 2010. The single became her fifth consecutive top twenty hit when it peaked at number eleven on the UK Singles Chart.
"Broken Arrow" was released on 10 October 2010 as the lead single (sixth overall) from the Turn It Up Louder reissue. The music video was directed by Gregg Masuak, and premiered on Lott's official YouTube account on 16 September 2010. The single reached number twelve on the UK chart, giving Lott her sixth consecutive top twenty single.
Although it was initially suggested that "Coming Home", a collaboration with American R&B singer Jason Derülo, would serve as the album's next single after it debuted at number fifty-one on the UK Singles Chart, Lott later confirmed on her official Twitter page that she was filming a video for "Can't Make This Over". The video premiered on 25 November 2010, but the single release was ultimately cancelled.
Turn It Up received mixed reviews from music critics. At Metacritic, which assigns a normalised rating out of 100 to reviews from mainstream critics, the album received an average score of 51, based on 8 reviews, which indicates "mixed or average reviews". Paul Lester of BBC Music described the album as a "classy, if not classic, debut from potential-rich pop newcomer" and stated that the songs on the album "do indeed sound as though they could be farmed out to other RnB starlets. That's a compliment as much as it is a criticism: from the 1960s soul stomp of her number one hit 'Mama Do (Uh Oh, Uh Oh)' to new single 'Boys & Girls' with its brassy Mark Ronson-esque production, some of the material here lacks character."Stephen Thomas Erlewine of Allmusic wrote, "Despite this fondness for swinging girl group sounds and Pixie's predilection for belting out the songs, Turn It Up doesn't play as a retro-soul throwback, the way Winehouse or Duffy do. Lott never attempts to seem wiser than her years, [...] and the production is wisely, slyly modern." Sarah-Louise James of Daily Star viewed that "the photogenic Essex lass seems to combine the best elements of all our favourite British pop divettes: the smoky growl of Wino, the big sultry pipes of Duffy and the pop sass of Sugababes."
Digital Spy music editor Nick Levine commented that "Turn It Up is never dull—Lott has too much natural exuberance for that—but it's a little safe and lacking in surprises", citing "Gravity", "Turn It Up" and "Here We Go Again" as highlights. Dan Cairns of The Sunday Times opined that "[b]ar two missteps ('My Love' and 'Nothing Compares'), Turn It Up is superior, infectious, expertly tailored pop that, had it been recorded 30 or so years ago, would very likely now be being praised to the heavens in reissue sections." Dan Gennoe of Yahoo! Music noted that "[t]he sass, swagger, killer hooks and big production have been focused on the obvious chart contenders and the rest of the album is, true to tradition, a lot of middle of the road balladry and overly earnest swaying, also known as filler."Daily Express reviewer Robert Spellman felt that the single "Mama Do (Uh Oh, Uh Oh)" "promised what the album hasn't delivered, a sort sultry self-confidence with a pinch of the wreckless that would do Lady Gaga proud", adding that "corny power ballads such as 'Cry Me Out' and too much half-baked R&B mistakenly attempt to give Pixie depth when she—or rather her writers—should be gunning for surface only."The Daily Telegraph's Helen Brown referred to Lott as "[f]un and feisty but hard to distinguish from the rest of this year's girl pop pack." In a review for musicOMH, Michael Cragg dismissed the album as "a fairly average pop album being strangled by a talented vocalist who equates loudness with emotion." Imogen Carter of The Observer compared the album to a Disney teen-film soundtrack, calling it "cloying and cliche-ridden, particularly the slow numbers."
Turn It Up debuted at number six on the UK Albums Chart, selling 25,652 copies in its first week. Following the album's re-release as Turn It Up Louder on 18 October 2010, it rose from number twenty-nine to number nine on 24 October 2010. Since its debut, it has spent ninety-seven non-consecutive weeks on the chart, five of which in the top ten and twenty-three in the top twenty. On 13 August 2010, the album earned a double platinum sales certification from the British Phonographic Industry (BPI), and had sold 855,805 copies in the UK by January 2012. Additionally, it became the UK's eighteenth best-selling album of 2010.
In Ireland, Turn It Up debuted and peaked at number eighteen on the Irish Albums Chart for the week of 17 September 2009, remaining on the chart for fifty-five weeks altogether. The album saw modest success across continental Europe, reaching number sixteen in Denmark, number twenty-four on the European Top 100 Albums chart, number forty-nine in Switzerland, number sixty in France, number seventy in Austria and Belgium's Wallonia, number eighty-one in Germany, number ninety-two in the Netherlands and number ninety-nine in Belgium's Flanders. In Oceania, it peaked at number eight on the Australian Hitseekers Albums Chart and at number thirty in New Zealand.
The enhanced CD includes a link to a bonus area on Push Entertainment, which can only be accessed by inserting the CD into one's CD/DVD drive, featuring videos of "Boys and Girls" and "Mama Do (Uh Oh, Uh Oh)" to watch online, and to download for free.