The pharmacokinetics of L-tryptophan following its intravenous and oral administration

Br J Clin Pharmacol. 1985 Oct;20(4):317-21. doi: 10.1111/j.1365-2125.1985.tb05070.x.


The pharmacokinetics of L-tryptophan (5 g and 7.5 g) have been studied after its intravenous administration to healthy subjects and the results compared with those obtained after oral administration (0.7 g-3.5 g). In order to do this, we have re-analysed previously published data relating to oral administration. The data obtained following the oral administration of L-tryptophan suggest that the total body clearance and apparent volume of distribution are saturable. The pharmacokinetics of tryptophan after intravenous administration of 5 g and 7.5 g were similar to those after the oral administration of 25 and 50 mg kg-1 (i.e. 1.75 g and 3.5 g). Similar pharmacokinetic values were obtained following intravenous tryptophan when the same subjects were retested after a period of 2-4 weeks.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Administration, Oral
  • Adult
  • Humans
  • Injections, Intravenous
  • Kinetics
  • Male
  • Time Factors
  • Tryptophan / administration & dosage
  • Tryptophan / metabolism*


  • Tryptophan