What happens when you quit Protein Powder?

Some protein powders have Creatine in it, that's why people are talking about it, OP. Just wanting to clarify that.
If the protein powder you chose has Creatine in it, I've read you'll gain some water weight, because the Creatine increases the water retained around your muscles. If you stop taking it, then the water retention will go away, which *might* cause a less defined look if you're bulking. Don't think it would leave you flabby so to speak though. Otherwise, nothing happens. You just stop taking it and that's the end of it.

Creatine doesn't increase water retention around the muscle instead it brings water into the muscle.

Yes, thank you for correcting me. This is what I meant to say, but I worded it very poorly

I'm looking to gain more weight. In a month I've put on 2 kgs purely using food but I find it hard to make my daily calorie goal so I want to start taking protein powder. My question is what happens after you stop using it?

Your wallet bulks up

Protein powder can be constipating. So you may find that you are more regular when you stop using it. Some people see it as a "cheat" to increase protien consumption in a bulk. I use it because organic, grass fed beef is too expensive.

I use Optimum Nutrition Gold Standard 100% whey protein. It is about .77 cents a serving, and is a very good quality protein.

Try to avoid soy and soy isolate protein. There is still more research that needs to be done, but early studies indicate that it may inhibit testosterone production and increase estrogen and progesterone levels, which is pretty much the opposite of what you want to happen to increase muscle mass.