Loreen became known to Swedish audiences after taking part in the Swedish Idol 2004 competing as Lorén Talhaoui. She was initially picked as a wildcard by the judges to join the singing competition. She finished 4th overall.
After Idol, in 2005, she released a promotional single, "The Snake", with the group Rob'n'Raz. Later in 2005 she became a television presenter with the Swedish station TV400 for a year and then took a hiatus from the limelight.
Melodifestivalen 2011: "My Heart Is Refusing Me"
Loreen returned to the public eye when she took part in Melodifestivalen 2011 with the song "My Heart Is Refusing Me", which she co-wrote with Moh Denebi and Björn Djupström. After placing fourth in the second semifinal in Gothenburg, she competed in the Second Chance round, but failed to qualify to the final after a sing-off with Sara Varga.
Melodifestivalen 2012: "Euphoria", Eurovision Song Contest
In the first semifinal of Melodifestivalen 2012 on 4 February, Loreen advanced directly to the final round with her entry "Euphoria", written by Thomas G:son and Peter Boström. She won the national final on 10 March with a combined total of 268 points and represented Sweden in the Eurovision Song Contest 2012 in Baku, Azerbaijan. The song won the competition with a total of 372 points from 40 voting countries out of 42. According to online betting companies she was the favourite to win the contest.