What Are The Side Effects Of Taking Diet Pills?

I have been interested in trying a diet pill. I am about 5'5 and 125 lbs. I still have my "pregnancy fat" around my waistline from having my daughter 3 years ago. My husband was recently deployed so unfortunately as much as I try to work out through the week it's not as much as I'd like due to I have nobody to watch my daughter. I was thinking of taking a diet pill for about a month or two just to kickstart my fat burning desire because I don't have much time to workout. Afterwards, I would continue with my regular workout routine in order to reach my desired results. Are the diet pills they sell at GNC safe or effective?? If so, what kind do you recommend? I've also heard of doctors prescribing diet pills to their patients. Are they certain prescribed diet pills that would be better and safer than those sold in stores?? Thank you in advance for your time!