Are there any type of pills to make your butt bigger?

I would think if there is pills that make your breats bigger then there are pills to make your rear end bigger too. Avoid pills. As in all things, there is no quick fix. You can develop your "butt" by doing leg exercises to develop your lower back and glutes. (I.e. lay on your stomach, lift legs one at a time for two sets of repetition.) It may take time, but you will at least be firmer. Alternatively, you could purchase some of the underwear that has padding in that area.