Green Tea catechins have been shown to help with weight loss. Animal studies showed that it helped suppress food intake and fat tissue accumulation, and human studies showed increases in metabolic rate and a mild increase in thermogenesis. (Komatsu et al., 2003; Kovacs et al., 2004)
So I say it works, but I also think there are other things that work even better, like TTA, EC, RK. One good combo is Genomyx DCP. Another option is to build your own. SNS carries alot of those single ingredients that allow you to dose it how you want.