Personally, I'd avoid a product like this at all costs. It's unregulated, so it's hard to tell what is or isn't in it. They don't have to prove anything to you as a consumer. There's no scientific evidence it works, and could have potentially dangerous side effects.
If you have a true problem with your appetite (most people don't overeat due to hunger), maybe it's best to ask your doctor for something. S/he will prescribe something that is proven to work, and s/he can monitor you for any side effects.
Just because it says 'natural' or 'herbal' doesn't make it safe. Many of these products are very dangerous.
Hope that helps