Narrator: This is Science Today. About 300 thousand Americans have what's called end stage renal disease, meaning they need some form of therapy to do the work their kidneys can no longer do. Dr. Kirsten Johansen, a kidney disease specialist at the University of California, San Francisco, says the vast majority of these patients are on hemodialysis.

Johansen: Because it's only three hundred thousand people, a lot of people really don't know much about it. Patients who have kidney disease sometimes think of dialysis being almost like death and they're very afraid of going on dialysis and dialysis isn't like that at all - people can survive years and years on dialysis. But it isn't perfect.

Narrator: One of the problems dialysis patients face is malnutrition, but Johansen has found that small doses of anabolic steroids helped these patients bulk up and fight fatigue.

Johansen: We're planning on a follow-up study where we're going to look again at the anabolic steroids and really do a little bit more investigating. What is happening in the muscles with this? And to look at weightlifting type of resistance exercise to see whether or not by itself that has comparable effects.

Narrator: For Science Today, I'm Larissa Branin.