Some have suggested that growth hormone is a wonder drug ( 16 ) that results in ripped muscle ( 17 ) and provides stamina-increasing properties ( 18 ) .
The use of human growth hormone to improve athletic performance has recently received worldwide attention .
This practice , often called sports doping , is banned by most professional sports leagues and associations , including the International Olympic Committee , Major League Baseball , and the National Football League ( 13 ) .
However , a wide range of athletes , including those from baseball ( 46 ) , cycling ( 7 , 8) , and track and field ( 5 , 9 ) , have been implicated in or have confessed to illicit growth hormone use .
The Mitchell report ( 10 ) recently identified 89 Major League Baseball players who allegedly used performance-enhancing drugs , and some of these players have subsequently admitted to using growth hormone ( 11 , 12 ) .
Part of the attraction of using growth hormone as a performance enhancer has been that its use is difficult to detect .
The World Anti-Doping Agency , whose formation stemmed from the widely publicized doping sc and al of the 1998 Tour de France ( 13 ) , first used a blood test to detect exogenous growth hormone during the 2004 Olympic Games in Athens .
Although growth hormone is reportedly used to enhance athletic performance and has been called the most anabolic substance known ( 15 ) , its efficacy for this purpose is not well established .
Exogenous growth hormone therapy in growth hormonedeficient adults ( that is , those with growth hormone deficiency due to hypothalamic or pituitary defects ) results in increased lean mass and decreased fat mass ( 19 ) , and comparable body composition changes are seen in healthy elderly adults who receive growth hormone ( 20 ) .
Some experts , however , have suggested that the strength-enhancing properties of growth hormone among healthy adults have been exaggerated ( 15 ) .
Serious side effects , including diabetes , hepatitis , and acute renal failure , may occur in athletes using high-dose growth hormone ( 21 ) .
Furthermore , the use of growth hormone for athletic enhancement is not approved by the U.S. Food and Drug Administration , and the distribution of growth hormone for this purpose is illegal in the United States ( 22 ) .
We performed a systematic review of r and omized , controlled trials to determine the effects of growth hormone therapy on athletic performance in healthy , physically fit , young adults .
Our primary aim was to evaluate the effects of growth hormone on body composition , strength , basal metabolism , and exercise capacity .
In addition , we sought to synthesize the evidence on adverse events associated with growth hormone in the healthy young and assess the quality of the published literature .
Short-term safety and efficacy of human GH replacement therapy in 595 adults with GH deficiency: a comparison of two dosage algorithms.
The aim of GH replacement therapy in GH-deficient adults is to optimize response with minimum incidence of adverse reactions , but optimal therapy regimens are still to be established . This two-arm parallel study examined effects of two GH dose algorithms in adults with GH deficiency of adult or childhood onset . Patients on low dose ( LD ; n = 302 )  received GH at 3 microg/kg per day for 3 months increasing to 6 microg/kg per day for 3 months , and those on conventional dose ( CD ; n = 293 ) started on 6 microg/kg per day for 3 months increasing to 12 microg/kg per day for 3 months . The proportion of patients completing therapy was greater for the LD group than the CD group for the first 3 months ( 93.0 % vs. 88.1 % ; P = 0.037 ) and overall for the 6 months ( 90.7 % vs. 84.0 % ; P = 0.013 ) . Both dose groups showed significant increases in lean body mass and decreases in fat mass for all time points . Percent increase in lean body mass was less with LD than CD over the first 3 months ( 2.43 + /- 4.33 vs. 3.58 + /- 4.69 % ; P = 0.006 ) but not overall for the 6-month period ( 4.38 % + /- 5.34 % vs. 5.21 % + /- 5.99 % ; P = 0.141 ) . Percent decrease in fat mass was less with LD than CD for the first 3 months ( -2.81 % + /- 7.81 % vs. -5.53 % + /- 8.64 % ; P < 0.001 ) and overall for the 6-month period ( -6.35 % + /- 9.42 % vs. -9.45 % + /- 12.07 % ; P = 0.006 ) . IGF-I SD score increased less with LD than CD for 0 to 3 and 0 to 6 months , although for IGF-binding protein-3 SD score , there was no significant difference between doses at any time . Arthralgia was the only adverse event that occurred significantly less frequently with LD than with CD . Calculated changes based on gender and onset indicated greater changes in males than females for body composition , but there was little difference in GH-related adverse events between males and females . The lower starting dose with dose titration appeared more favorable , but differences in response between genders and onset of GH deficiency need to be taken into account when setting an individual dose regimen
Some have suggested that growth hormone is a wonder drug ( 16 ) that results in ripped muscle ( 17 ) and provides stamina-increasing properties ( 18 ) .
The use of human growth hormone to improve athletic performance has recently received worldwide attention .
This practice , often called sports doping , is banned by most professional sports leagues and associations , including the International Olympic Committee , Major League Baseball , and the National Football League ( 13 ) .
However , a wide range of athletes , including those from baseball ( 46 ) , cycling ( 7 , 8) , and track and field ( 5 , 9 ) , have been implicated in or have confessed to illicit growth hormone use .
The Mitchell report ( 10 ) recently identified 89 Major League Baseball players who allegedly used performance-enhancing drugs , and some of these players have subsequently admitted to using growth hormone ( 11 , 12 ) .
Part of the attraction of using growth hormone as a performance enhancer has been that its use is difficult to detect .
The World Anti-Doping Agency , whose formation stemmed from the widely publicized doping sc and al of the 1998 Tour de France ( 13 ) , first used a blood test to detect exogenous growth hormone during the 2004 Olympic Games in Athens .
Although growth hormone is reportedly used to enhance athletic performance and has been called the most anabolic substance known ( 15 ) , its efficacy for this purpose is not well established .
Exogenous growth hormone therapy in growth hormonedeficient adults ( that is , those with growth hormone deficiency due to hypothalamic or pituitary defects ) results in increased lean mass and decreased fat mass ( 19 ) , and comparable body composition changes are seen in healthy elderly adults who receive growth hormone ( 20 ) .
Some experts , however , have suggested that the strength-enhancing properties of growth hormone among healthy adults have been exaggerated ( 15 ) .
Serious side effects , including diabetes , hepatitis , and acute renal failure , may occur in athletes using high-dose growth hormone ( 21 ) .
Furthermore , the use of growth hormone for athletic enhancement is not approved by the U.S. Food and Drug Administration , and the distribution of growth hormone for this purpose is illegal in the United States ( 22 ) .
We performed a systematic review of r and omized , controlled trials to determine the effects of growth hormone therapy on athletic performance in healthy , physically fit , young adults .
Our primary aim was to evaluate the effects of growth hormone on body composition , strength , basal metabolism , and exercise capacity .
In addition , we sought to synthesize the evidence on adverse events associated with growth hormone in the healthy young and assess the quality of the published literature .