Why do they tell you that you need a day to rest following a natural liver cleanse?

Does it wear you out?Why do they tell you that you need a day to rest following a natural liver cleanse?
I would think it might make you feel weak for a day or so.....Why do they tell you that you need a day to rest following a natural liver cleanse?
There is no such thing as a ';liver cleanse';. It's just a way to take your money! Eat healthy, take a good multi-vitamin %26amp; exercise. The body is built to cleanse itself %26amp; the liver is the organ with the most functions.