Abstract: A method for reducing potential adverse effects of androgenic testosterone precursors by interfering with production or action of testosterone and estrogen metabolites by nutrient combinations is described. Although androgenic testosterone precursors themselves have little or no toxicity, there is the potential for their metabolites, estradiol and dihydrotestosterone, to enhance or cause hormone-responsive illnesses such as breast or prostatic cancer, benign prostatic hyperplasia, or hirsutism or acne in women. The use of the invented nutrient combinations reduces the formation or action of estradiol and dihydrotestosterone, thereby reducing potential adverse effects from increased production of these hormones following androgenic testosterone precursor administration. This may be accomplished without negating the effects of testosterone on muscle anabolism.