The 22-year-old actress has experimented with various chemical treatments and extensions on her hair in the past, reported Daily star.
"She's been sporting a shorter do for weeks, and has made out it's for style reasons. But really she chopped her hair off because it's been falling out of her head," a source said.
"Jennifer's had so many chemical treatments and extensions the only thing she could do to make her hair healthy again was to start over. She's getting really paranoid about it," the source added.