Not to be confused with dehydroepiandrosterone (DHEA), 7-Keto DHEA is a metabolite of DHEA, which is formed in the adrenal glands.1 Human production of DHEA normally peaks during the mid-20s, and then begins a steady, progressive decrease of up to 90 percent with aging.2 This decrease is associated with a host of age-related syndromes and conditions, including a concurrent reduction in protein formation, a decrease in muscle mass and an increase in body fat.3 There are no good dietary sources of DHEA.
Although DHEA has received a lot of press for its potential ability to slow the aging process, 7-Keto DHEA may prove to be a safer alternative. Unlike DHEA, 7-Keto-DHEA is not converted to androgens and estrogens.4 Oral or topical administration of 7-Keto-DHEA does not affect plasma levels of steroid hormones.5 Similarly to DHEA, 7-Keto-DHEA is rapidly converted to the sulfated form, known as 7-Keto-DHEAS.6 The half-life of 7-Keto-DHEAS is about 2.17 hours, the time to peak plasma levels is about 2.2 hours, and the apparent volume of distribution is about 540 L.7
Researchers have identified three major areas of potential benefit for individuals 40 or older: weight loss, cognitive function and immune function. The most well-known of these is weight loss, where 7-Keto-DHEA is thought to be beneficial by increasing metabolism and thermogenesis. Early evidence in animals suggests 7-Keto-DHEA can increase thermogenesis, possibly by stimulation of thermogenic enzymes in the liver and impact thyroid function, positively impacting metabolism.8
Human research is promising. In one study, 30 overweight adults were randomized into a prospective, double blind, placebo-controlled eight-week study, and received placebo or 100 mg of 7-Keto DHEA twice daily.9 All subjects exercised three times per week, 60 minutes per session of cross-training (aerobic and anaerobic) under the supervision of an exercise physiologist. The exercise plus 7-Keto DHEA group lost a significant amount of body weight as compared with the exercise plus placebo group. When analyzed as a four-week interval, the 7-Keto DHEA group lost 3.17 lbs per interval, whereas placebo lost 1.09 lbs. In terms of actual body composition changes, the exercise plus 7-Keto DHEA group lost 1.8 percent body fat as compared to 0.57 percent for the placebo group. In addition, 7-Keto-DHEA was seen to significantly increase levels of the thyroid hormone triiodothyronine (T3).