One human trial used 100 mg per day in an attempt to increase testosterone levels, however, ideal intake remains unknown.


Androstenedione (andro) is an androgen hormone. It is produced in the adrenal glands and gonads from dehydroepiandrosterone (DHEA) or 17 alpha-hydroxyprogesterone and is converted to testosterone by several tissues, including muscle and bone. One trial reported that 100 mg of andro raised testosterone levels in women to six times the normal range, and was significantly more effective in this than a similar amount of DHEA.1 In men, andro supplementation at 300 mg per day raised both testosterone and estrogen levels in one controlled trial2 and raised only estrogen levels in another.3 Lower amounts of 100 mg per day raised estrogen but had no effect on testosterone levels in these and other4 trials. Strength and muscle mass gains were measured in two of these studies, which found no benefit from 100 mg of andro per day alone5 or 300 mg of andro per day during an eight-week weight training regimen.6

Substances similar to andro, such as androstenediol and norandrostenedione, are also available. While some test tube and animal studies have found androgen-like effects7 as well as immune-enhancing effects8 for androstenediol, no research exists on the effects of supplementing these substances in the human body.

Animal studies have demonstrated a protective effect of androstenedione against bone loss when normal hormone production is reduced.9