Both athletes and the general population use nutritional supplements. Athletes often turn to supplements hoping that consuming the supplement will help them be more competitive and healthy, while the general population hopes to improve body image or vitality. While many supplements contain ingredients that may have useful properties, there are supplements that are contaminated with compounds that are banned for use in sport or have been deliberately adulterated to fortify a supplement with an ingredient that will produce the advertised effect. In the present study, we have used yeast cell and mammalian cell androgen bioassays to characterize the androgenic bioactivity of 112 sports supplements available from the Australian market, either over the counter or via the Internet. All 112 products did not declare an androgen on the label as an included ingredient. Our findings show that six out of 112 supplements had strong androgenic bioactivity in the yeast cell bioassay, indicating products spiked or contaminated with androgens. The mammalian cell bioassay confirmed the strong androgenic bioactivity of five out of six positive supplements. Supplement 6 was metabolized to weaker androgenic bioactivity in the mammalian cells. Further to this, Supplement 6 was positive in a yeast cell progestin bioassay. Together, these findings highlight that nutritional supplements, taken without medical supervision, could expose or predispose users to the adverse consequences of androgen abuse. The findings reinforce the need to increase awareness of the dangers of nutritional supplements and highlight the challenges that clinicians face in the fast-growing market of nutritional supplements.
Keywords: performance enhancement; sports doping; steroids; undeclared androgens.