I have some clen that expired Feb/05. But my question is how much of the potency has been gone my know? I just started a six weeks cycle with two weeks on and two weeks off. I started with 40 mcg,80mcg,120mcg,160,mcg and now Iam taking 200mcg and don't feel any side effects,the only side effect that i get is heartburns. I don't know is that is normal. I taken this clen before it expired and i could feel the side effects at 120mcg. I still have around 200 tabs so I dont know if I should keep taking them or throw them in the garbage. I would appreciate if somebody can give me there opinion.