I have been taking flomax for a couple of years now. The benefit has been urinating a few times less a day. I don't sleep well. Lately, I have been have mild, not real painful, like a dull pain headaches. I do get dizzy upon standing more frequently lately, I do not recall the dizziness until just recently. But my big side effect is loss of erection during sex and/or voluntary erection. I never had this problem before. I workout five days a week, three cardio days and two days in the weight room. I also take lisinopril for blood pressure and lovastatin for chloresterol. Great to hear other men are experiencing these same side effects.