Britney Full of Bull

1/22/2007 1:54 PM PST BY TMZ STAFF
Britney Spears must be low on energy, because the pop star pumps the Red Bull non-stop. Maybe it's because she starts work at 7:30 PM?

The extension-stressed pop mom was spotted heading into Hollywood's Record Plant Recording Studios in the early evening hours on Friday.

Hopefully, she still has a voice; clearly her sense of style has vanished.