Enzyme induction by oral testosterone

Clin Pharmacol Ther. 1976 Aug;20(2):233-7. doi: 10.1002/cpt1976202233.


Six normal male volunteers ingested a dose of 400 mg free testosterone daily as tablets over 21 days. By the end of treatment intravenous antipyrine half-life had decreased significantly from 8.0 +/- 2.7 to 5.7 +/- 2.6 hr. The subjects eliminated testosterone from serum more rapidly on the twenty-first day of testosterone ingestion than on the first day. Serum albumin, bilirubin, prothrombin, alanine-amino-transferase, and alkaline phosphatases were unchanged during the experiment. It is concluded that oral testosterone treatment induces the hepatic drug-metabolizing system including that of testosterone.

PIP: The effects of high doses of testosterone on liver function was studied in 6 healthy males. Intravenous antipyrine elimination was used as the primary parameter of liver function. The subjects received 400 mg testosterone orally for 20 days. The half-life of antipyrine decreased from a mean of 8 + or -2.7 to 5.7 + or -2.6 hours by the end of treatment. Excretion of testosterone was significantly (p greater than .0005) higher on Day 21 of the experiment than on Day 1. Treatment had no apparent effect on serum levels of albumin, bilirubin, prothrombin, alanine-amino-transferase, and alkaline phosphatases. It is concluded that orally administered testosterone induces its own enzymatic metabolism.

MeSH terms

  • Administration, Oral
  • Adult
  • Antipyrine / blood
  • Depression, Chemical
  • Enzyme Induction / drug effects*
  • Half-Life
  • Humans
  • Liver Function Tests
  • Male
  • Testosterone / administration & dosage
  • Testosterone / metabolism
  • Testosterone / pharmacology*
  • Time Factors


  • Testosterone
  • Antipyrine