Detox products promise to rid your body of vague toxins. The reality: you already have a sophisticated detox system — your liver and kidneys continuously filter and remove waste and harmful substances. There's no good evidence that juice cleanses or detox teas remove toxins better, and they can backfire: very low-calorie cleanses can cause fatigue, and some detox teas contain laxatives that cause fluid loss mistaken for fat loss.
If you want to support your body's own detoxification, the unglamorous basics work: drink water, eat plenty of fiber and vegetables, limit alcohol, don't smoke, and sleep well. Save your money — a cleanse won't out-perform a working liver.