Yes run them together but make sure you're doing daily cardio as that will make your body stronger and it will help keep yourself lean. Then make sure you're eating a quality diet. If you want more appetite, take the MK in the morning.
When you come off of it you can expect a rebound effect but remember it's a drug. Also remember it's been shown to be safe when used for a long time. That's why a lot of diabetics are using them long term with success.