The "Margin Call" and "Ghost" star went to the rehab center after a brief hospitalization following a seizure-like episode she suffered at a party Jan. 23.
E! News said Moore sought treatment for drug addiction and an eating disorder but has since left the facility and is now on vacation at an undisclosed location.
"She's in no rush to get back to LA," the insider said. "She's on total lock-down and only talking to a small group of people."
The 49-year-old "About Last Night" and "St. Elmo's Fire" actress is the mother of three grown daughters with her ex-husband, film star Bruce Willis. Her marriage to actor Ashton Kutcher recently ended.