This is adapted from the book, Eat Smart, Play Hard, by RW USA Nutrition Editor Liz Applegate.
Better known as andro, this supplement made headlines when US baseball slugger Mark McGwire said that andro, along with the supplement creatine, helped him to build muscle mass. Andro quickly sold out of stores while scientists tried to find out whether the supplement worked and if it was safe.
In both cases, the verdict was no. Natural androstenedione is a hormone secreted by your adrenal glands. Companies who make the supplement claim that supplemental andro boosts levels of the hormone testosterone, helping to build muscle mass and sex drive. But when scientists tested it in the lab, they found that the supplement did not improve muscle mass, body composition, or libido. It did lower healthy HDL cholesterol levels, however.
One study published in the prestigious Journal of the American Medical Association found that while andro did not boost testosterone or muscle mass, it did boost estrogen, which is dangerous for men. Among other things, the supplement may increase the risk of male breast enlargement, cancer, and heart disease.
My recommendation: Leave andro to gather dust on the restocked shelves.