The most common side effects I've heard or seen in others is an increase in water retention, and feelings of dehydration. Creatine draws water from the body into the muscles and can make them appear slightly bloated. This will diminish once you've stopped taking the supplement, as will some of the weight you've gained.
I recommend adopting a better diet for optimal muscle growth. There are plenty of meal plans made for bodybuilders on the net.
Here's one you can check out:
http://www.bodybuilding.com/fun/musclebuilding_essentials.htm
Hi. There is no current study that prohibits Atomoxetine (Strattera) users to take creatine supplements. However, caution should be made when taking supplements, since both drugs can alter kidney function and cause urinary symptoms (e.g. stones, dysuria) when not taken properly. I suggest that you ask your doctor first if these are safe for you to use. Thanks for asking.