Androstenedione has been shown to increase serum testosterone levels over an eight-hour period in men when taken as a single oral dose of 300 mg per day, but a dose of 100 mg had no significant effect on serum testosterone.[10] However, serum levels of estradiol increased following both the 100 mg and 300 mg doses.[10] The study also reported that the serum level of estrogens and testosterone produced varied widely between individuals.[10]