The X Factor USA judge is said to have been handed a recent Vogue article which stated that Barlow's hair was the nation's most-requested by men.
Since reading the article, he has now allegedly asked his advisors to "explore new hairstyles".
"Simon's make-up girl and hairdresser showed him a feature in Vogue that said Gary had the No.1 requested haircut," a source told The Sun.
"Simon read it, every single word, had a think and then sent her away to explore new hairstyles.
"Everyone was having a chuckle about it when they heard.
"He has spared no expense on the old research either. They are presenting him with computer-enhanced hairdos with his face attached for him to approve."
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Cowell was recently quoted in Tom Bower's book Sweet Revenge as calling Barlow's appearance on The X Factor "too scripted".
It was also claimed that he was upset with the Take That singer's OBE award.
Gary Barlow recently stated that he has no time for "tittle tattle" about his personal life.
Watch Gary Barlow and the Overs talk to Digital Spy about The X Factor below: