Drug Free Sport Staff Writers

Drug Free Sport Staff Writers

Monday, December 19, 2016

Testosterone Boosters

Dietary supplements claiming to boost testosterone or enhance sexual performance are often explored and inquired about by athletes. However, these products come with concerns. Many of the ingredients are created in factories, making them unnatural, and lack scientific evidence regarding their safety and efficacy, even if the products are labeled as “herbal” or “all natural” (Campbell et al., 2013).

The Food and Drug Administration (FDA) holds dietary supplement manufacturers responsible for truth in labeling and safety of all dietary supplement products that enter the consumer market. Unfortunately, these companies may not list each product ingredient on the supplement facts panel, can make false or exaggerated claims, and/or add harmful ingredients. Due to the unregulated nature of supplements, there is little data regarding the products as a whole, including the ingredients, use of proprietary blends, and marketing claims (Willoughby, Spillane, & Schwarz, 2014).

Testosterone boosters and sexual enhancement products have a higher risk of containing harmful ingredients that are not listed on the label, compared to other supplement categories. For example, phosphodiesterase type 5 (PDE5) inhibitors are pharmaceutical medications used to treat erectile dysfunction. PDE5 inhibitors have been found in testosterone boosting and sexual enhancement supplements, but have not been listed on the product label. In 2013, researchers tested sexual performance supplements to determine if they were adulterated with PDE5 inhibitors or other undeclared ingredients. The marketing for all 54 tested supplements claimed they did not contain synthetic substances. However, 81% of the tested products contained one or more synthetic PDE5 inhibitor or similar ingredient, undisclosed to the consumer (Campbell et al., 2013).

Taking dietary supplements that “boost testosterone” have proven ineffective in reducing fat mass, as well as increasing total body or muscle mass. Instead, products making these claims come with a lot of unknowns and dangers (Willoughby et al., 2014).

Consumers are made to believe that testosterone levels and muscle mass will increase with the use of dietary supplements claiming to be testosterone boosters. Manufacturers even state that their product is scientifically proven to work. When in reality, they often contain dietary ingredients that have not been tested for efficacy or safety.

Tribulus terrestris (TT) is a popular herbal ingredient found in testosterone boosting supplements. TT is associated with claims of boosting testosterone and correcting erectile function. Physically-active men are the target market for products containing TT (Pokrywka, 2014). Similarly, TT allegedly improves plasma testosterone levels and increases skeletal muscle growth (Antonio, Uelmen, Rodriguez, & Earnest, 2000). The use of dietary supplements with TT has shown no substantiated benefits in human studies. As with most dietary ingredients, there is a lack of evidence-based information regarding the effectiveness and safety of TT use in sport (Pokrywka, 2014). The consumer should be aware that many herbal/all-natural ingredients claiming to boost testosterone levels or provide other anabolic effects have limited scientific support.

Drug Free Sport believes that food should be the first option for fueling when athletes are looking to reach performance goals. Dietary supplements are poorly regulated by the FDA, with manufacturers loosely following the FDA’s guidelines. Supplement companies market their products how they wish, often place unlabeled ingredients in the bottle, and make false claims. Appropriately-timed meals and snacks, on the other hand, have been proven to aid in weight reduction and achieving sports performance goals.

If you are thinking about taking any dietary supplement, please visit Drug Free Sport AXIS to learn more about your options to make an informed decision. 


Antonio, J., Uelmen, J., Rodriguez, R., & Earnest, C. (2000). The effects of tribulus terrestris on body composition and exercise performance in resistance-trained males. International Journal of Sport Nutrition and Exercise Metabolism, 10, 208-215.

Campbell, N., Clark, J.P., Stecher, V.J., Thomas, J.W., Callanan, A.C., Donnelly, B.F.,… Kaminetsky, J.C. (2013). Adulteration of purported herbal and natural sexual performance enhancement dietary supplements with synthetic phosphodiesterase type 5 inhibitors. International Society for Sexual Medicine, 10, 1842-1849.

Pokrywka, A., Obminski, Z., Malczewska-Lenczowska, J., Fijatek, Z., Turek-Lepa, E., & Grucza, R. (2014). Insights into supplements with tribulus terrestris used by athletes. Journal of Human Kinetics, 41, 99-105.

Qureshi, A., Naughton, D.P., & Petroczi, A. (2014). A systematic review on the herbal extract tribulus terrestris and the roots of its putative aphrodisiac and performance enhancing effect. Journal of Dietary Supplements, 11(1), 64-79.

Willoughby, D.S., Spillane, M., & Schwarz, N. (2014). Heavy resistance training and supplementation with the alleged testosterone booster NMDA has on effect on body composition, muscle performance, and serum hormones associated with the hypothalamo-pituitary-gonadal axis in resistance-trained males. Journal of Sports Science and Medicine, 13, 192-199.