I started using Clen 2 days ago. I had a mild headache the first day, but yesterday the pain was worse. I've had sinus headaches before, and this is sinus related. Usual OTC pain meds (motrin, tylenol) didn't touch it. I did take a sinus headache med, which helped for a few hours - then I was back where I started from. This morning I noticed definate tenderness around my eyes - again, sinus? Has anyone had this problem, and if so, what do you do to alleviate the discomfort?