Testosterone Boosters: How Real Are Their Effects?

Abstract

In the past decade, there has been an increased interest in alternative treatments to testosterone (T) and androgen derivatives. This has led to the development of supplements known as "testosterone boosters"(T-boosters) or "testosterone enhancers."The internet is the main source for the purchase of these products with sales reaching millions of dollars. The search for T-boosters is focused on improvement in sexual performance, muscular strength, and increased muscle mass using agents considered "natural,"which are thereby presumed to lack serious adverse effects. Some of these supplements have been used since antiquity. Commercially sold T-boosters nearly always comprise multiple supplements, and none of these combinations have undergone rigorous evaluations, as would be required for regulatory approval for pharmaceutical products. This makes it challenging to evaluate marketing claims. However, a limited scientific literature does exist for the primary individual agents in most T-boosters. The most commonly used agents are Tribulus terrestris, fenugreek, zinc, maca, and ashwaganda ("Indian ginseng"). Those studies form the basis of this review. Although some studies have offered suggestive results indicating possible increases in serum T, the data are inconsistent, and studies differ widely in methods, including supplement dosage. In addition, serious adverse events have been reported. Currently, the existing literature fails to support the use of these products.