Androstenedione Supplements Not Helpful, Maybe Harmful

There is mounting evidence that the testosterone precursor androstenedione, which is available as a nonprescription supplement, is ineffective and may cause harm. Tennessee researchers randomly assigned 50 men (age range, 35 to 65) to twice-daily treatments of placebo, androstenedione (100 mg), or androstenediol (100 mg), a secondary prohormone often found with androstenedione in supplements. All 3 groups participated in intense strength training 3 times weekly for 12 weeks.

At baseline, subjects were moderately active and had, on average, about 20 percent body fat. Participants who received androstenedione showed a transient increase in free testosterone, but at 12 weeks testosterone levels returned to baseline and were comparable to those …