It works in advance, but the rebound is particularly severe, so it is not recommended for you to use it. If you want to lose weight, I'll give you two ways. 1. Find a 2 1 day diet from Baidu. This is a test because you need to be hungry. 2 1 day lost 20 Jin. Although I lose weight quickly, I don't recommend it. 2. Diet+exercise. As the saying goes, shut up and take your legs. Eat less greasy food, and save dinner if you can. If you have time to run, not every day, but at least twice a week. 45 minutes each time. Go if you can't run. The effect is the same. I hope I can help you.