Human growth hormone certainly builds muscles, but it may not make athletes faster or stronger. "What we found suggested that it didn't help—and at some point, it might hurt," said the lead investigator on the Stanford research study. So why, the San Jose Mercury News wonders, do sports stars risk their careers by turning to HGH?
All of the studies under scrutiny looked at low doses of the hormone, and the higher doses taken by athletes may have very different effects. Doping players are also likely to include HGH in a wider regimen of performance enhancers such as steroids and insulin. The scientists admit that they still can't answer the question, "How do you hit a baseball further?"