British pop star Robbie Williams has confessed he has undergone a drastic hair replacement procedure. The former Take That singer has a home in Los Angeles and often feels under pressure to fit in with other stars by having cosmetic surgery to keep him looking young. Now he has admitted he once underwent a procedure to improve the thickness of his tresses - even though his hairline was not receding. Williams tells U.K. talk show host Graham Norton, "I've lived in L.A. for a long time and they say, 'If you sit in a barber's shop for long enough you will get a haircut'. Well, if you live in Los Angeles for long enough you're going to get some surgery. I've had a thatch done and I didn't even need it. That's the weirdest thing. I had three months off and got bored."