title: Effect of Ginkgo biloba extract on plasma steroid concentrations in healthy volunteers: a pilot study.
abstract: OBJECTIVE
  To determine if a standardized ginkgo supplement significantly alters concentrations of circulating androgenic steroids in humans.
  
  
  METHODS
  Open-label, fixed-treatment order, crossover study.
  
  
  METHODS
  University general clinical research center.
  
  
  METHODS
  Eleven healthy volunteers (six men, five women).
  
  
  METHODS
  Volunteers received ginkgo biloba 240 mg/day for 14 days.
  
  
  RESULTS
  Plasma concentrations of cortisol, 11-deoxycortisol, 17alpha-hydroxyprogesterone, testosterone, dihydrotestosterone, dehydroepiandrosterone sulfate, sex hormone-binding globulin, androstenedione, and free testosterone, as well as free androgen index and combined concentrations of androsterone sulfate and epiandrosterone sulfate, were analyzed in all subjects before and after their 14-day course of ginkgo biloba. Ginkgo biloba did not significantly alter endogenous steroid levels compared with baseline values (p < 0.05).
  
  
  CONCLUSIONS
  A 14-day oral administration of a widely used, standardized ginkgo extract at a generally advocated dosage of 240 mg/day did not significantly alter concentrations of major circulating steroids in men and women.
authors.affiliation: Department of Pharmaceutical Sciences, Medical University of South Carolina, Children's Research Institute, Charleston, South Carolina 29425, USA. markowij@musc.edu
authors.forename: John S
authors.initials: JS
authors.lastname: Markowitz
authors.forename: C Lindsay
authors.initials: CL
authors.lastname: DeVane
authors.forename: John G
authors.initials: JG
authors.lastname: Lewis
authors.forename: Kenneth D
authors.initials: KD
authors.lastname: Chavin
authors.forename: Jun-Sheng
authors.initials: JS
authors.lastname: Wang
authors.forename: Jennifer L
authors.initials: JL
authors.lastname: Donovan
mesh_terms: D000328:Adult; D000735:Androstenedione / Q000097:blood; D018592:Cross-Over Studies; D019314:Dehydroepiandrosterone Sulfate / Q000097:blood; D013196:Dihydrotestosterone / Q000097:blood; D005260:Female; D020441:Ginkgo biloba; D006801:Humans; D006854:Hydrocortisone / Q000097:blood; D008297:Male; D010865:Pilot Projects; D010936:Plant Extracts / Q000494:pharmacology*; D012738:Sex Hormone-Binding Globulin / Q000032:analysis; D013256:Steroids / Q000097:blood*; D013739:Testosterone / Q000097:blood; D000096983:Ginkgo Extract
chemical_list: D000735:Androstenedione; D019314:Dehydroepiandrosterone Sulfate; D013196:Dihydrotestosterone; D006854:Hydrocortisone; D010936:Plant Extracts; D012738:Sex Hormone-Binding Globulin; D013256:Steroids; D013739:Testosterone; C063170:Ginkgo biloba extract; D000096983:Ginkgo Extract