Depending on what diet pills your taking. Most Rx speed up your metabolism and in a result they will eat threw your pill faster. I’m on phentermine to help lose some baby weight. I notice some spotting brown and red for about a week and a half in the middle of the month but I did get my period on time. I would call your pharmacist and ask, it doesn’t madder if its over the counter or not. Hope this helped!
The only side effects that you will get are from the diet pills. Diet pills can cause heart attacks and even death. Just exercise, and you will be fine. Don't waste your money on something like that. Most contain orange oil, which is about the same as ephedra.