ll say 25 mg once a day is a very low dose and hope your get some feed back from others on
side effects. It seems they vary greatly person to person. For me 50 mg a day has minimal side effects, but yes, it does cause some fatigue. I am also in permanent atrial fibrillation which may be the real issue for me. I had taken Toprolol when much younger and in normal sinus rhythm (then it too was 50mg SR) and it had no side effects that I can recall, I was still running for exercise.