The website is reporting that Moore has left Utah's Cirque Lodge, a treatment center favored by celebrities, and is "on vacation" from Los Angeles at an undisclosed location.
"She's in no rush to get back to L.A.," a source told E! "She's on total lockdown and only talking to a small group of people."
The actress' rep did not respond immediately to ABCNews.com's request for comment.
E! first reported that Moore checked into Cirque following her brief hospitalization in Los Angeles after she suffered seizure-like symptoms during a party at her home on Jan. 23.
According to the website, the "Margin Call" actress sought help for addiction issues and an eating disorder.
After Moore was hospitalized, her rep said the actress was seeking treatment for exhaustion. However, a recording of the 911 call placed before Moore was taken to the hospital indicated that she'd been "smoking something" and had experienced seizure-like symptoms.