Recently, the legal "steroid alternative" androstenedione has received a great amount of attention in the lay press, mostly due to the publicity surrounding Mark McGwire's homerun feats in 1998. Manufacturers tout it as a safe substitute for banned anabolic steroids, such as testosterone, and claim that it allows its users to swiftly build muscle mass and recover more quickly from injuries (Josefson, 1998). There exist very few studies confirming the scientific claims of the drug's producers, and as with many dietary supplements the rationale for its usage is mostly theoretical and anecdotal.

Androstenedione is an anabolic steroid that is naturally produced inside the body by the adrenal gland and gonads, and it is converted by an enzyme (17B- hydroxysteroid dehydrogenase) in the liver into testosterone and various estrogens (King et al., 1999). The reasoning behind using androstenedione to augment strength and performance gains lies in the fact that it is naturally converted to testosterone, a steroid with known performance-enhancing qualities. Thus, theoretically if androstenedione is added to the body, an increase in circulating testosterone will be produced.

Until recently, no well-designed study on the safety and efficacy of androstenedione had been published. In the June 2, 1999 issue of the Journal of the American Medical Association (JAMA), King et al. published the results of a randomized controlled study on the effect of androstenedione on blood testosterone levels and strength training in young men. They found that those receiving androstenedione supplementation (300 mg/day) did not exhibit increased testosterone levels or produce higher strength gains than the group taking a placebo. Additionally, they noted that the androstenedione group showed increased levels of 2 estrogens (estradiol and estrone) and decreased levels of high-density lipoproteins (HDLs) - the "good cholesterol". These results suggest that ingesting androstenedione does not promote conversion into testosterone, but instead into estrogen, which could have serious health consequences. Furthermore, the reduction in HDL cholesterol levels could have adverse heart and vascular implications if androstenedione is used for extended periods of time.

The scientific research on this subject is very limited, and the above study represents the first attempt to rigorously examine the effects of androstenedione. It is clear that more extensive work is needed to validate or refute the claims of the supplement manufacturers. However, based the early information that is available from a well-designed scientific study, it not only appears that androstenedione supplementation produces none of the desired outcomes (increased testosterone levels, enhances muscle strength), but elicits harmful side effects that potentially could have serious health implications.

References:

King DS, Sharp RL, Vukovich MD, Brown GA, Reifenrath TA, Uhl NL, Parsons KA. Effect of Oral Androstenedione on Serum Testosterone and Adaptations to Resistance Training in Young Men: A Randomized Controlled Trial. JAMA. 1999; 281: 2020-28.

Josefson D. Concern Raised About Performance Enhancing Drugs in the US. BMJ. 1998; 317: 702.