A few weeks ago, a reader asked me to post some links to studies on the ergogenic properties of androstenedione, more commonly known as “andro”, after I stated there is little evidence of its performance-enhancing qualities. I was reminded of my promise to post the abstracts when I stumbled across some PED studies while cleaning off my desk. I also found some more studies that find little performance-enhancing effects from growth hormone (HGH or GH), and I will post those abstracts in the near future.
The first study below was being presented as a conference paper just as Mark McGwire’s andro use became known during his historic home-run-record chase in 1998. I have heard that exercise physiologists got a real kick out of the media spectacle in light of the timing of this paper.
Effect of Oral Androstenedione on Serum Testosterone and Adaptations to Resistance Training in Young Men: A Randomized Controlled Trial
Authors: Douglas S. King, PhD; Rick L. Sharp, PhD; Matthew D. Vukovich, PhD; Gregory A. Brown, MS; Tracy A. Reifenrath, MS; Nathaniel L. Uhl; Kerry A. Parsons, MS
Journal of the American Medical Association. 1999;281:2020-2028.
Context Androstenedione, a precursor to testosterone, is marketed to increase blood testosterone concentrations as a natural alternative to anabolic steroid use. However, whether androstenedione actually increases blood testosterone levels or produces anabolic androgenic effects is not known. Objectives To determine if short- and long-term oral androstenedione supplementation in men increases serum testosterone levels and skeletal muscle fiber size and strength and to examine its effect on blood lipids and markers of liver function. Design and Setting Eight-week randomized controlled trial conducted between February and June 1998. Participants Thirty healthy, normotestosterogenic men (aged 19-29 years) not taking any nutritional supplements or androgenic-anabolic steroids or engaged in resistance training. Interventions Twenty subjects performed 8 weeks of whole-body resistance training. During weeks 1, 2, 4, 5, 7, and 8, the men were randomized to either androstenedione, 300 mg/d (n=10), or placebo (n=10). The effect of a single 100-mg androstenedione dose on serum testosterone and estrogen concentrations was determined in 10 men. Main Outcome Measures Changes in serum testosterone and estrogen concentrations, muscle strength, muscle fiber cross-sectional area, body composition, blood lipids, and liver transaminase activities based on assessments before and after short- and long-term androstenedione administration. Results Serum free and total testosterone concentrations were not affected by short- or long-term androstenedione administration. Serum estradiol concentration (mean [SEM]) was higher (P< .05) in the androstenedione group after 2 (310  pmol/L), 5 (300  pmol/L), and 8 (280  pmol/L) weeks compared with presupplementation values (220  pmol/L). The serum estrone concentration was significantly higher (P<.05) after 2 (153  pmol/L) and 5 (142  pmol/L) weeks of androstenedione supplementation compared with baseline (106  pmol/L). Knee extension strength increased significantly (P<.05) and similarly in the placebo (770  N vs 1095  N) and androstenedione (717  N vs 1024  N) groups. The increase of the mean cross-sectional area of type 2 muscle fibers was also similar in androstenedione (4703  vs 5307  mm2; P<.05) and placebo (5271  vs 5728  mm2; P<.05) groups. The significant (P<.05) increases in lean body mass and decreases in fat mass were also not different in the androstenedione and placebo groups. In the androstenedione group, the serum high-density lipoprotein cholesterol concentration was reduced after 2 weeks (1.09 [0.08] mmol/L [42 (3) mg/dL] vs 0.96 [0.08] mmol/L [37 (3) mg/dL]; P<.05 ) and remained low after 5 and 8 weeks of training and supplementation. > Conclusions Androstenedione supplementation does not increase serum testosterone concentrations or enhance skeletal muscle adaptations to resistance training in normotestosterogenic young men and may result in adverse health consequences.
Author: Michael E. Powers
Journal of Athletic Training 2002 Jul;37(3):300-305.
Objective: Anabolic steroid precursors have gained widespread popularity as ergogenic supplements. Advertisements for these supplements claim that they increase endogenous testosterone production and protein synthesis, resulting in increased lean body mass and strength during training. At this time scientific support is limited, but the potential for serious side effects exists and the popularity of these supplements continues to grow. This review provides rationales for the ergogenic claims regarding steroid precursors and compares claims with data from scientifically controlled investigations. Data Sources: A search of MEDLINE and SPORT Discus from 1960 to 2001 using the key words dehydroepiandrosterone, androstenedione, and androstenediol in combination with testosterone, estrogen, exercise, performance, and side effects. Data Synthesis: Although fairly new to the athletic community, steroid precursors have been used as ergogenic or anabolic agents for quite some time. Suggested gains in strength and lean body mass are attributed to an increase in the endogenous production of testosterone and enhanced protein synthesis. Most of the scientific data, however, do not support manufacturers’ ergogenic claims, and the potential for serious side effects, such as decreased high-density lipoprotein cholesterol and increased estrogen concentrations, has been associated with precursor use. Thus, the safety and efficacy of these supplements must be questioned. Conclusions/Recommendations: It appears that the risks associated with the use of anabolic steroid precursors outweigh any possible ergogenic benefits. Furthermore, these supplements are banned by most athletic organizations. Thus, it is extremely important that athletic trainers are able to educate athletes on these issues so they can continue to perform at an optimum level in a safe and healthy manner.