Being lazy I have copied and pasted this from a more detailed response. Short answer yes it could.
Protein supplements are big money so people are encouraged to waste their money and time using them rather than buying better food.
There is a limit to how much protein your body can absorb at a time, 17g normally or 25g during or just after exercise, and I mean just after. This means unless your protein drink is just after training 7g will go to making your stool more bound up, and in truth that is not the worst that can happen.
If you take in more protein than you need and it gets into the blood stream it will be in the form of amino acids, no shock to most there. The part the purveyors of these supplements leave out is that amino acids are the nutritional equivalent of time bombs, stable for a while then becoming toxic as they break down to ammonia, there is good news however the body is ready for this and has ways to tackle them before they become toxic. First is to convert any it can to lipoproteins, which is fat made from amino acids, and put it to fat stores, fat gain, just what you wanted no doubt. The second is to make the remaining aminos safe by converting them to urea and flushing them out with a load of water, which can give short term weight loss followed by the body rehydrating itself and yes this does put strain on the kidneys.
Protein supplements are a con. To keep it simple muscle is predominantly water, drinking twice as much water as you need will not make you more muscular, neither will eating twice as much protein, it is truly that simple.