Hi. I do take magnesium glycinate 100 mg x 3 daily. When I first took it I found myself pleasantly drowsy in the late evenings and fell asleep quickly. But I still woke up 2-3 hours later, per usual. Then when I started Iodine supplementation I found myself alert (although not "wired") until a least an hour later each evening. Thankfully I can still fall asleep fairly quickly.
Or I should put it another way: Iodine gives me an extra hour of productivity every day. Priceless, IMHO.