I'm using this right now. No negative effects for me for the last month. It's helpful in conjunction with my low-carb diet. I don't feel like garbage during induction. It does bump my metabolism, and I've been running around my house like a mad woman cleaning for the last few weeks. Along with cardio! Can't beat it. It's nice. No weird fluctuations, and it curbs my appetite.
First major goal to lose 10% of my 355lb weight Jan 1, 2013 (35.5lbs=319.5)!! MET IT ON FEB 2014!!
Next goal 20% of my 355lb weight (20% = 284#)
1 dancing marshmallow for every 5 pounds I lose to not look like one anymore!