title: Oral androstenedione administration and serum testosterone concentrations in young men.
abstract: BACKGROUND
  Androstenedione, a steroid hormone and the major precursor to testosterone, is available without prescription and is purported to increase strength and athletic performance. The hormonal effects of androstenedione, however, are unknown.
  
  
  OBJECTIVE
  To determine if oral administration of androstenedione increases serum testosterone levels in healthy men.
  
  
  METHODS
  Open-label randomized controlled trial conducted between October 1998 and April 1999.
  
  
  METHODS
  General clinical research center of a tertiary-care, university-affiliated hospital.
  
  
  METHODS
  Forty-two healthy men aged 20 to 40 years.
  
  
  METHODS
  Subjects were randomized to receive oral androstenedione (either 100 mg/d [n = 15] or 300 mg/d [n = 14]) or no androstenedione (n = 13) for 7 days.
  
  
  METHODS
  Changes in serum testosterone, androstenedione, estrone, and estradiol levels, measured by frequent blood sampling, compared among the 3 treatment groups.
  
  
  RESULTS
  Mean (SE) changes in the area under the curve (AUC) for serum testosterone concentrations were -2% (7%), -4% (4%), and 34% (14%) in the groups receiving 0, 100, and 300 mg/d of androstenedione, respectively. When compared with the control group, the change in testosterone AUC was significant for the 300-mg/d group (P<.001) but not for the 100-mg/d group (P = .48). Baseline testosterone levels, drawn 24 hours after androstenedione administration, did not change. Mean (SE) changes in the AUC for serum estradiol concentrations were 4% (6%), 42% (12%), and 128% (24%) in the groups receiving 0, 100, and 300 mg/d of androstenedione, respectively. When compared with the control group, the change in the estradiol AUC was significant for both the 300-mg/d (P<.001) and 100-mg/d (P = .002) groups. There was marked variability in individual responses for all measured sex steroids.
  
  
  CONCLUSIONS
  Our data suggest that oral androstenedione, when given in dosages of 300 mg/d, increases serum testosterone and estradiol concentrations in some healthy men.
authors.affiliation: Department of Medicine, Massachusetts General Hospital, Boston 02114, USA.
authors.forename: B Z
authors.initials: BZ
authors.lastname: Leder
authors.forename: C
authors.initials: C
authors.lastname: Longcope
authors.forename: D H
authors.initials: DH
authors.lastname: Catlin
authors.forename: B
authors.initials: B
authors.lastname: Ahrens
authors.forename: D A
authors.initials: DA
authors.lastname: Schoenfeld
authors.forename: J S
authors.initials: JS
authors.lastname: Finkelstein
mesh_terms: D000284:Administration, Oral; D000328:Adult; D000735:Androstenedione / Q000008:administration & dosage / Q000097:blood / Q000494:pharmacology*; D019540:Area Under Curve; D004958:Estradiol / Q000097:blood; D004970:Estrone / Q000097:blood; D006801:Humans; D008297:Male; D013739:Testosterone / Q000097:blood* / Q000378:metabolism
chemical_list: D004970:Estrone; D013739:Testosterone; D000735:Androstenedione; D004958:Estradiol