I started taking it at night a few weeks ago after reading many of the comments. I first had a horrific headache and have had one about once a week but not so bad as well as fatigue toward the early afternoon which I am not fighting but taking a nap (first time in my life for naps!). A cousin in the family said she has headaches about once a week but that things settle down. Shall keep on keeping on and see how it goes.