syn. 3beta-hydroxy-5-androsten-17-one syn. prasterone
Dehydroepiandrosterone (DHEA) is a steroid hormone produced mainly in the adrenal glands. It is one of the most abundant steroid hormones in humans, although its exact biological role remains unclear. DHEA is known to serve as an indirect precursor to many sex steroids, including estrogen and testosterone.291 DHEA itself has also been shown to be a weak androgen,292 although in a practical sense it is considered to be devoid of significant anabolic or androgenic activity. It is believed to have some supportive action in the immune system, potentially countering the suppressive effects of the stress hormone cortisol.293 DHEA is also regarded as an active component in the central nervous systems,294 may be involved in IGF-1 synthesis,295 and appears to have some cortisol inhibiting (protein sparing) effect.296
The level of dehydroepiandrosterone in the blood tends to get lower with age, and is especially low in the elderly.297,298 This DHEA reduction mirrors the age related decline in testosterone synthesis. When associated with physical symptoms, this testosterone decline is medically identified as andropause, and often treated with supplemental testosterone. Given the potential precursor relationship to testosterone (as well as the natural lowering of DHEA), dehydroepiandrosterone has been widely sold as a non-prescription anti-aging and hormone replacement supplement for men and women. Its exact therapeutic value in this context, however, remains unclear.299,300 DHEA is also widely available as a sports nutrition product due to its theoretical potential for increasing the musclebuilding effects of testosterone.
DHEA is two steps away (metabolically) from testosterone. It must first be converted to either androstenedione or androstenediol. This indirect conversion makes DHEA a very ineffective oral testosterone precursor. It appears that this hormone does not significantly contribute to the synthesis of testosterone in men. Even high doses (1,600 mg) have been shown to be ineffective at raising blood testosterone levels.301 Thus far, significant testosterone elevations have been reported in postmenopausal women only.302,303 Men tend to notice only minor shifts in estrogen and IGF1. Studies do suggest there is potential for DHEA to improve exercise performance in the elderly of both sexes, possibly through testosterone-independent mechanisms.304 It appears unlikely, however, that DHEA supplementation will have testosterone-elevating or ergogenic effects in healthy exercising young men.
DHEA is promoted to increase testosterone levels, and support muscle mass and strength gains.
DHEA has been shown to improve body composition in placebo-controlled studies with sedentary (untrained) adults. It has a Clinical Support Rating of 4 (4/5).
One placebo-controlled study examined the effects of high doses of DHEA on body composition and hormone levels in a group of healthy men.305 Subjects took 1,600 mg of DHEA per day for four weeks. There was no exercise as part of this study. The use of DHEA was associated with a 31% reduction in fat mass, with no change in total body weight. This suggests the weight loss was associated with an increase in skeletal muscle mass. In spite of this high dose, there was no change in total testosterone, free testosterone, or estrogen levels.
Another placebo-controlled study examined the effects of long-term DHEA supplementation on exercise performance in elderly subjects.306 The dosage used was 50 mg per day, which was taken for 10 months. During the last four months all participants were subject to a controlled heavy resistance training program. The subjects taking DHEA noticed greater improvements in muscle strength (knee extension torque and knee flexion torque) compared to those taking the placebo. Testosterone levels increased significantly (300%) only in female subjects taking DHEA. Estrogen levels increased 30% and 70% in supplemented men and women, respectively. Levels of IGF-1 (Insulin-like Growth Factor 1) also increased slightly in both men and women taking DHEA.
Studies with younger populations taking DHEA as an adjunct to exercise have not yielded the same positive results. For example, one placebo-controlled study examined the effects of DHEA on exercise performance in a group of young men.307 Subjects took a dose of 150 mg per day for eight weeks, during which time they followed a controlled resistance training program. The use of DHEA did not produce statistically significant improvements in testosterone levels, muscle strength, or lean body mass compared to placebo.
Another placebo-controlled study looked at the effects of dehydroepiandrosterone in a group of healthy trained (> 1 year experience) men.308 Subjects took 100 mg per day for a period of 12 weeks. The use of DHEA did not produce a statistically significant increase in serum testosterone levels, lean body mass, or exercise performance (muscle strength) compared to placebo.
While these studies do not support the use of DHEA as an ergogenic aid in young exercising populations, they do suggest the supplement might improve body composition and exercise performance in elderly men and women.
DHEA is widely available as a stand-alone supplement. The feedback on its use in sports nutrition tends to be negative. To begin with, men who use this product as a testosterone booster in the hopes it will increase muscle mass and strength generally wind up disappointed. It is rare to find reports of noticeable anabolic or androgenic effects from young men taking DHEA. This seems in line with clinical studies showing that DHEA is not effective at raising testosterone levels or improving exercise performance in young men. However, this supplement does appear to offer some ergogenic value in women, as well as the elderly of both sexes. Were we focusing on vitality and “anti-aging” use in older people, DHEA would warrant a strong empirical evidence rating (4/5), as it is often very highly regarded amongst these consumers. As it stands for our purposes, DHEA receives an overall Empirical Evidence Rating of 2 (2/5), given its weak application as an ergogen in sports nutrition.
Based on clinical studies, a dosage of 50-200 mg per day is recommended in elderly exercising men and women. An effective dosage in young exercising individuals has not been established.
Side Effects / Safety:
DHEA was well tolerated during clinical studies, with no significant side effects reported.