Sure it works. It'll suppress your apetite and boosts energy/increases metabolism (contains caffeine). But obviously, nobody is going to get into fantastic shape by just drinking Green Tea, or by merely taking a single supplement for that matter. Supplements only offer a little boost...the thing that really works is having a good exercise/diet plan.
You can find Green Tea in any
Health food store (like GNC). You can even find capsuled Green Tea (more convenient to take a pill sometimes than to drink a cup of tea).