I think it's because of the long half-life: it's about 15 hours. I have over half a bottle from when I was prescribed it (for MS fatigue) and I can definitely

I think it's because of the long half-life: it's about 15 hours. I have over half a bottle from when I was prescribed it (for MS fatigue) and I can definitely still feel in my system after a day. And yeah, if I take it more than, say, 2 days in a row, I start having a bad time.