Metabolism in rats of p-cymene derivatives: carvacrol and thymol

Pharmacol Toxicol. 1987 Aug;61(2):98-102. doi: 10.1111/j.1600-0773.1987.tb01783.x.


The metabolism of carvacrol and thymol in rats was studied using gas chromatographic-mass spectrometric methods. The urinary excretion of metabolites was rapid. Only very small amounts were excreted after 24 hrs. Although large quantities of carvacrol and, especially, thymol were excreted unchanged (or as their glucuronide and sulphate conjugates), extensive oxidation of the methyl and isopropyl groups also occurred. This resulted in the formation of derivatives of benzyl alcohol and 2-phenylpropanol and their corresponding carboxylic acids. In contrast, ring hydroxylation of the two phenols was a minor reaction.

MeSH terms

  • Animals
  • Biotransformation
  • Cymenes
  • Gas Chromatography-Mass Spectrometry
  • Hydroxylation
  • Male
  • Monoterpenes*
  • Rats
  • Terpenes / metabolism*
  • Terpenes / urine
  • Thymol / metabolism*
  • Thymol / urine


  • Cymenes
  • Monoterpenes
  • Terpenes
  • 4-cymene
  • Thymol