Eatting more calories than you need makes you gain weight.
There are just as many calories in protien as there are in carbs.
if you have worked out how many calories you need and you are including the protein suppliment in your daily requirements then there is no problem. but if you dont eat well then its not going to help.
Also, its far better to get your protein from whole foods if you can, use a supliment if and when you have to.