Is DHEA the only adrenal hormone?
More than 150 hormones are known to be synthesized by the adrenal glands (see diagram next page for a general overview). However, the most abundant hormone made by the adrenal glands is DHEA. We'll discuss the adrenal glands in more detail in Appendix A.
After DHEA is made by these glands it goes into the bloodstream, and from then on it travels all over the body and goes into our cells, where it is converted into male hormones, known as androgens, or female hormones, known as estrogens (Drucker, 1972). Whether DHEA gets converted predominantly into androgens or estrogens depends on a person's medical condition, age, and sex. Every person has a unique biochemistry.
In males the testicles also make androgens, while in females, before menopause, the ovaries also make estrogens. So the body has developed at least two organs where sex steroids are made. After menopause, the ovaries no longer make estrogens. DHEA is also thought to be made in the brain.
How much DHEA does our body make?
Humans are thought to make between 1 and 2 mg of DHEA and between 10 and 15 mg of DHEAS a day (Longcope, 1995 and personal communication), although higher estimates– up to 25 mg– have been made. These numbers are lower for women by about 10 to 30%.
How is DHEAS different from DHEA?
When DHEA is metabolized, a chemical called sulfate is added. Sulfate consists of the mineral sulfur combined with oxygen (SO4). Thus DHEAS stands for DHEA-sulfate.
DHEA is mostly made in the morning hours. Its levels decline fairly rapidly during the day because it is quickly cleared by the kidneys. However, DHEAS is cleared much more slowly and blood levels remain much more stable throughout the day (Longcope, 1995). About 90% of this hormone in the blood is in the DHEAS form; the rest circulates as DHEA. That is why, when researchers want to assess blood levels for DHEA, they often measure DHEAS levels.
When you take DHEA supplements, some will circulate in your bloodstream as DHEA, but most of it will be sulfated by your liver to circulate as DHEAS.
Will taking DHEA supplements suppress my adrenal gland's natural DHEA production?
The production of most hormones is controlled by a "feedback loop," which means that when hormone levels get too high, the body is told to make less, and when hormone levels are too low, the body is told to make more. Cortisol, testosterone, and estrogen are all regulated by this feedback. In other words, if you take cortisol, or a similar derivative such as prednisone, it will shut off your body's natural production.
Fortunately, DHEA appears to be one of the exceptions. According to Dr. Peter Hornsby at the Baylor College School of Medicine in Houston, Texas, there doesn't seem to be a feedback mechanism for DHEA or DHEAS. In other words, DHEA supplements, except perhaps in very high dosages, are not likely to stop our body's own production, although there are no long-term human studies to confirm this.
Where does the DHEA that I buy come from?
The DHEA pills that you buy are made by vitamin and pharmaceutical companies. They extract sterols from wild yams, the most common sterol being diosgenin. After cleaving a few side chains from diosgenin in the laboratory, DHEA is produced.