What Causes Pimples Like Blisters On Hips And Back?

Hi doctor, i used a food supplement named like mega mass because i use to do gym, but after using that i got heat in my body and pimples started to come on my face, back and hips. I went to skin specialist, he gave me skin antibiotics. Pimples on face are gone now but they are like same on the hips, just like boils and are filled with water and are painful. What should i do to get rid of them? Its been a long time they are continuously coming.