A new study by the U.S. researchers published on Monday reported that people using human growth hormone breaking the law are not all benefited by the substance’s use. The study led by Dr. Hau Liu of Stanford University in California, reported while some illegal steroids may help athletes bulk up and train harder, human growth hormone is not one of them.

In a telephonic interview, Dr. Hau Liu said, "What we saw is that while there was a change in body composition, we didn't find evidence that growth hormone improves athletic performance."

Reviewing 27 studies covering 303 people aged 13 to 45, Dr. Hau Liu and his team found that overall, those who took growth hormone did develop more lean body mass, but this did not translate to either more strength or exercise capacity. The people using growth hormone had swelling of their tissues and more fatigue compared to people not taking the drug, they added. However, when the hormone is given to people with growth hormone deficits caused by pituitary tumors or other conditions, it can improve strength. But it does not enhance strength in normal, healthy people.

Dr. Andrew Hoffman, a professor of endocrinology, gerontology and metabolism who worked on the study, said, "The key takeaway is that we don't have any good scientific evidence that growth hormone improves athletic performance."

According to Hoffman, other hormones have been shown to benefit athletes -- notably testosterone. That’s why Athletes probably take much more hormone than the investigators felt that they could ethically try to give to healthy people; in addition, some athletes combine growth hormone with other anabolic hormones like testosterone. But, they get side-effects from high doses of hormones.
Hoffman said, "You get fluid accumulating in the legs, you get pain in the joints from what we hear the athletes are taking very, very large doses"

“Other hormones do, however bulk up athletes -- although not without risk. The findings with growth hormone absolutely do not extend to other hormones like testosterone which work through entirely different mechanisms," Hoffman said.

It’s important to note here that the use of growth hormone is banned by the International Olympic Committee, Major League Baseball and the National Football League. U.S. law prohibits its use for sports enhancement.