There is nothing in the herb world that I have found to kill my appetite. Even during my phen fen trials, I was on quite a high dose and still craved certain things. Some herbs that may work for you. Stimulants tend to suppress appetite in some people, but can also be dangerous. Herbs containing caffeine such as tea, kola nut and guarana and ephedra are especially popular and can be dangerous.
Speed freaks end up with more problems than it's worth.
You may be able to lose 10 lbs in water, or if you are one of the few with actual metabolism problems. I take herbs to increase my metabolism, but my appetite increases. Yes, so does mine. This is where you need to change your habits. What ever you do, don't eat more of the wrong things, your only defeating the purpose.