clen question

hey guys i did clen a while back and it worked really well. anyways i have the same clen now and it doesnt feel like its working. am i immune to it or something? when i took it last i could feel by heart beating faster, couldnt sleep at night, and i had the shakes. i dont know what to do. maybe up the does? somebody please help me.
How long ago did you take it for the first time? How long has the break been? What dosages are you using?
Pretty sure you mean 20mcg, but was that the same dosage as you started out during the last time that you used it? Also, are you monitoring your body temperature when you are taking it?
yeah i started out at 20mcg a day and upped the does daily. the last time i did it i was sloppy, i didnt monitor my body temp but this time i'm more serious about it.