The effect of androstenedione intake on serum hormone concentrations in women is equivocal. Therefore, we examined the hormonal response to androstenedione intake in healthy young (22.1 +/- 0.4 y) women for 4 hours. On day 3 of the follicular phase, subjects ingested placebo, 100, or 300 mg androstenedione in a random, double-blind, cross-over manner. Blood samples were collected before and every 30 min for 240 min after intake. Serum androstenedione concentrations (means +/- SE) increased above basal (6.2 +/- 0.8 nmol/l) from 60-240 min for both 100 mg (22.6 +/- 1.0 nmol/l at 240 min) and 300 mg (28.1 +/- 1.3 nmol/l at 210 min). Androstenedione intake increased serum total testosterone concentrations above basal (1.2 +/- 0.2 nmol/l) from 120-240 min (5.5 +/- 0.9 nmol/l at 210 min) with 100 mg and from 60-240 with 300 mg (10.2 +/- 1.6 nmol/l at 210 min). Androstenedione intake also increased serum estradiol concentrations (basal 191 +/- 24 pmol/l) at 150 min with 100 mg (237 +/- 35 pmol/l) and from 150-240 min with 300 mg (reaching 260 +/- 32 pmol/l at 240 min). These data indicate that, in contrast to men, androstenedione intake in women increases serum testosterone concentrations.

The following study examined the acute hormonal response to androstenedione ingestion in eight college-aged females. Between days three and five of the follicular phase and between 6am and 9am, subjects ingested placebo (100 mg rice pill), 100, or 300 mg of androstenedione in a random, double-blind, cross-over manner. Blood samples were collected before and every 30 min for 240 min post ingestion. Androstenedione ingestion increased serum androstenedione concentrations (basal 6.2 ± 0.8 nmol/L) at each time point from 60 to 240 min for both 100 mg (peak at 240 min = 22.6 ± 1.0 nmol/L) and 300 mg (peak at 210 min= 28.1 ± 1.3 nmol/L). Ingestion of 300 mg resulted in higher androstenedione concentrations at each time point from 120 to 240 min. Ingestion of androstenedione increased serum estradiol concentrations (basal 191 ± 24 pmol/L) only at 150 min with 100 mg (237 ± 35 pmol/L) and at each time point from 150 to 240 min with 300 mg (peak at 240 min = 260 ± 32 pmol/L). Androstenedione ingestion increased serum total testosterone concentrations (basal 1.2 ± 0.2 nmol/L) at each time point from 120 to 240 min (peak at 210 min = 5.5 ± 0.9 nmol/L) with 100 mg and from 60 to 240 min with 300 mg (peak at 210 min= 10.2 ± 1.6 nmol/L). Ingestion of 300 mg androstenedione caused a larger increase than the 100 mg at each time point from 120 to 240 min. These data suggest that androstenedione ingestion by young females results in significant increases in serum total testosterone concentration and other significant changes in the hormonal profile.