Life Beyonce lost 20 pounds with a juice cleanse. Here are the pros and cons of the crash detox February 15, 2019 Rasha Ali, USA TODAY Comments Off on Beyonce lost 20 pounds with a juice cleanse. Here are the pros and cons of the crash detox A juice cleanse is when people drink nothing but fresh vegetable and fruit juice medleys in an effort to detox their body and lose weight.