I run clen 4 on 3 off for 3-4 weeks at 100mcg per day. I feel it (Still have the shakes) on day 5 sometimes 6. It seems to stay with me. Is your heart rate still ok?. Have you tried to back the dose down a bit?
Heart rate is fine, I have a tough time reacting to any substance. This just recently started to happen, so my first guess was it was clen. Maybe I am getting sick or something who knows.