DHEA was banned from over-the-counter sales in 1985 by the FDA. Because of the Dietary Supplement Health and Education Act, DHEA was reclassified as a food supplement. This androgen precursor was first identified in 1934 and is produced naturally by the zona reticularis cells of the adrenal glands.
The exact function of DHEA in the human body is not fully known, but scientists do know that it is a metabolic precursor to testosterone. DHEA may also increase levels of IGF-1 and may have a stimulatory effect on neurotransmitter receptors.
Three biologically active forms of DHEA are found circulating in plasma (DHEA, DHEA-S, and DHEA). Like other sex steroids, DHEA circulates in blood bound to a protein (albumin) and is easily
converted to other androgens and estrogen. DHEA and DHEA sulfate (DHEA-S) are converted peripherally to androstenedione, testosterone, and dihydrotestosterone. It can also be aromatized to estrogens via the enzyme P450 aromatase. Factors that influence these conversions are not well understood, but both aerobic and resistance exercise may playa role in the formation of various androgens or a decrease thereof.
The research on DHEA has mostly tested older subjects, not young athletes. For some individuals, supplementing with DHEA might restore feelings of youthfulness. A gap in the literature comes when we look at DHEA’s effects in younger males, especially bodybuilders.
To date, two studies looking at DHEA in those producing normal amounts of the hormone have been conducted. Welle et al. used 1600 mg of DHEA for 4 weeks in a double-blind, placebo-controlled crossover study in men (average age, 26 yrs). With supplementation, serum levels of DHEA increased, but there was no significant effect on body weight, body mass, resting metabolic rate, proteolysis, total energy expenditure, or cholesterol.
In a study by Nestler et al., 10 young men were divided into a placebo versus DHEA-supplemented (1600 mg/day) group for 28-day treatment duration. There was no effect on serum total testosterone, free testosterone, SHBG, estradiol, or estrone concentrations.
However, there was a slight decrease in body fat and a decrease in serum low-density lipoprotein cholesterol in the DHEA-supplemented men. Tissue sensitivity to insulin remained unchanged. This study and the one discussed previously illustrate that DHEA research is still in its infancy. Previous data from animal research by Han et al. showed that DHEA might be a potent antiobesity agent. However, at best DHEA produces only modest changes in body composition in humans.
Thus, DHEA’s applications in medicine could be far-reaching, but it is not clear whether DHEA is useful as an ergogenic aid.