A recent study published in the journal Age, found that testosterone replacement therapy leads to increases in lean muscle mass and decreases in overall body fat in older men.
Researchers examined the results of 11 previously run placebo-controlled studies in which testosterone replacement therapy was administered in men whose testosterone levels were below 550 ng/dl.
The review found that men in these studies who received testosterone replacement saw a significant increase in lean muscle mass, whereas those who were given a placebo did not. The increases in muscle mass varied from 3.6 to 13.6 pounds between individuals.
Testosterone replacement therapy was also found to lead to an average reduction in body fat by 1.78 percent.
Researchers concluded that the difference in the described outcomes can be explained by the fact that in each study, patients received different amounts of testosterone during varying time periods and through different methods of administration, which include patches, injections and topical gels.