The study surveyed more than 10,000 teen athletes and non-athletes. It found 12 percent of boys report supplement use, and eight percent of girls report supplement use.
The most common products are protein powder and shakes. Doctors say these are not harmful, but the other reported used products such as creatine, amino acids, and DHEA are of concern.
Doctors say there are no studies looking at the safety of these supplements. Because of this they say teens and adults should stay away from using them.
The study found supplement use was not just by athletes, but others striving for the perfect "beach body."