There are so many weight loss products available. But I think you should try only those natural weight loss products which are made with natural supplements. This will help you in reducing your weight.
I never use this product. Because for reducing fat, I mostly prefer to do exercise or workout. But somebody also suggest me to take fat burner product. Then I use that and it really works.
Vivarin is product having lot of Caffeine. I never use this product before. So I don't have any idea is it helpful or not for reducing weight. But I use Garcinia Cambogia product which helps me lot in reducing my fat and weight. I think you should try this one.