Abstract

The effectiveness of orally ingested androstenediol in raising serum testosterone concentrations may be limited because of hepatic breakdown of the ingested androgens. Because androstenediol administered sublingually with cyclodextrin bypasses first-pass hepatic catabolism, we evaluated the acute hormonal response to sublingual cyclodextrin androstenediol supplement in young men. Eight men (22.9 +/- 1.2 yr) experienced in strength training consumed either 20 mg androstenediol in a sublingual cyclodextrin tablet (Sl Diol) or placebo (Pl) separated by at least 1 wk in a randomized, double-blind, crossover manner. Blood samples were collected before supplementation and at 30-min intervals for 3 h after supplementation. Serum hormone concentrations did not change with Pl. Serum androstenedione concentrations were increased (P < 0.05) above baseline (11.2 +/- 1.1 nmol/l) with Sl Diol from 60 to 180 min after intake and reached a peak concentration of 25.2 +/- 2.9 nmol/l at 120 min. Serum free testosterone concentrations were increased from 86.2 +/- 9.1 pmol/l with Sl Diol from 30 to 180 min and reached a peak concentration of 175.4 +/- 12.2 pmol/l at 60 min. Serum total testosterone concentrations increased above basal (25.6 +/- 2.3 nmol/l) from 30 to 180 min with Sl Diol and reached a peak concentration of 47.9 + 2.9 nmol/l at 60 min. Serum estradiol concentrations were elevated (P < 0.05) above baseline (0.08 +/- 0.01 nmol/l) from 30 to 180 min with Sl Diol and reached 0.14 +/- 0.02 nmol/l at 180 min. These data indicate that sublingual cyclodextrin androstenediol intake increases serum androstenedione, free testosterone, total testosterone, and estradiol concentrations.