I am on day 3 with phen and I have not seen a difference. No headache, no dry mouth, no anxiety, no rapid heart, no energy. I'm happy I don't, but does that mean it's not working? I haven't noticed a difference in my appetite either? I have taken a half pill the first day and then yesterday I took it with food, today I took a full one on empty stomach. I just need this to work out.