Same with me, I was taking oxide tablets and decided to switch to Natural calm. I had the sleepy morning issue, as well as MAJOR anger issues. I was a raving wench. It took me 5 days to realize it, and after a couple days off I was fine. I have not tried to go back on yet. I am in the middle of a stressful time, so when things ease up I might try 1/4 tsp for a few days, see if it still effects me, and go from there. Might just be I don't need anymore magnesium, who knows. I have chronic muscle tension so I would like to be able to take it during flare ups to help out.