Common side effects include an increase in anxiety (feeling very jittery), sleep disturbances (either feeling drowsy, or insomnia), some GI symptoms which could include some nausea, diarrhea, lack of appetite, or increase in appetite. Also, headaches
are commonly reported. The good news is, these side effects
are short lived, with most people seeing improvements at about week 2. Also, not everyone will have side effects, it's something that greatly varies from person to person.