Although use of human growth hormone is prohibited by the World Anti-Doping Agency for use by competitive athletes, its effect on athletic performance has not been well studied. Now, reportedly for the first time, scientists in Australia have found that the substance has a positive effect on physical performance (Meinhardt U et al. Ann Intern Med. 2010;152:568-577).
In the study of adult recreational athletes (mean age, 27 years), 63 men were randomly assigned to receive placebo, human growth hormone, testosterone, or both hormones; 33 women were randomly assigned to receive placebo or growth hormone. All participants underwent physical performance testing before and after 8 weeks of treatment and after a 6-week washout period.