Effects of a purported aromatase and 5α-reductase inhibitor on hormone profiles in college-age men

Int J Sport Nutr Exerc Metab. 2010 Dec;20(6):457-65. doi: 10.1123/ijsnem.20.6.457.

Abstract

The purpose of this study was to determine the effects of an alleged aromatase and 5-α reductase inhibitor (AI) on strength, body composition, and hormonal profiles in resistance-trained men. Thirty resistance-trained men were randomly assigned in a double-blind manner to ingest 500 mg of either a placebo (PL) or AI once per day for 8 wk. Participants participated in a 4-d/wk resistance-training program for 8 wk. At Weeks 0, 4, and 8, body composition, 1-repetition-maximum (1RM) bench press and leg press, muscle endurance, anaerobic power, and hormonal profiles were assessed. Statistical analyses used a 2-way ANOVA with repeated measures for all criterion variables (p ≤ .05). Significant Group × Time interaction effects occurred over the 8-wk period for percent body fat (AI: -1.77% ± 1.52%, PL: -0.55% ± 1.72%; p = .048), total testosterone (AI: 0.97 ± 2.67 ng/ml, PL: -2.10 ± 3.75 ng/ml; p = .018), and bioavailable testosterone (AI: 1.32 ± 3.45 ng/ml, PL: -1.69 ± 3.94 ng/ml; p = .049). Significant main effects for time (p ≤ .05) were noted for bench- and leg-press 1RM, lean body mass, and estradiol. No significant changes were detected among groups for Wingate peak or mean power, total body weight, dihydrotestosterone, hemodynamic variables, or clinical safety data (p > .05). The authors concluded that 500 mg of dailyAI supplementation significantly affected percent body fat, total testosterone, and bioavailable testosterone compared with a placebo in a double-blind fashion.

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • 5-alpha Reductase Inhibitors / blood
  • 5-alpha Reductase Inhibitors / pharmacology*
  • Adipose Tissue / drug effects
  • Adult
  • Analysis of Variance
  • Aromatase Inhibitors / blood
  • Aromatase Inhibitors / pharmacology*
  • Body Composition / drug effects
  • Dietary Supplements
  • Dihydrotestosterone / blood*
  • Double-Blind Method
  • Estradiol / blood*
  • Humans
  • Male
  • Muscle, Skeletal / drug effects
  • Physical Endurance / drug effects
  • Resistance Training
  • Testosterone / blood*
  • Time Factors
  • Trigonella*
  • Young Adult

Substances

  • 5-alpha Reductase Inhibitors
  • Aromatase Inhibitors
  • Dihydrotestosterone
  • Testosterone
  • Estradiol