Britney Spears entered rehab Tuesday after a bizarre weekend that included shaving her head and getting a tattoo.
Spears' manager, Larry Rudolph, told People magazine's website that Spears, 25, had voluntarily checked herself into an undisclosed treatment facility.
"We ask that the media respect her privacy as well as those of her family and friends at this time," Rudolph was quoted as saying.
Since she announced her separation from Kevin Federline in November, Spears, the mother of two young sons, has been seen partying with Paris Hilton, and her appearance has been increasingly sloppy.
On Friday night, Spears grabbed an electrical shaver at a San Fernando Valley salon and shaved her head bald.
On Monday night, host Craig Ferguson told viewers of CBS' "The Late Late Show" that he wasn't going to make jokes about Spears, saying "she clearly needs help."
"For me, comedy should have a certain amount of joy in it," Ferguson said. "It should be about attacking the powerful -- the politicians, the Trumps, the blowhards -- going after them. We shouldn't be attacking the vulnerable."