Can whey protein plump your legs and butt?

The only thing that can grow muscles is exercise. Protein will help but if you don’t exercise its just going to turn into fat.

Yes whey protein concentrate has been linked to acne.

Yes, protein helps to grow muscles. But growing muscles is not the same as “plumping”. “Getting plump” is also know as getting fat.

Consider toning your muscles by running and other exercises. You want some good toning for your glutes? Start running stairs. A lot.