Both green tea and caffeine are quite potent natural stims, but they are obviously not as potent as ephedrine. So yeah - it will feel like taking a very strong coffee, but I highly doubt it will come even close to the ephedrine in terms of stimulatory effects. However, none of them are good for fat loss. Using stims for this purpose is never a good idea, since they will also increase cortisol levels, which will eat up your muscles as well. And this is not a healthy thing to use. Why not use instead much safer and more effective compounds, such as Cardarine GW or SR9009?