Plasma-kinetic characteristics of purified and isolated green tea catechin epigallocatechin gallate (EGCG) after 10 days repeated dosing in healthy volunteers

Int J Vitam Nutr Res. 2004 Jul;74(4):269-78. doi: 10.1024/0300-9831.74.4.269.


This randomized, double-blind, placebo-controlled study assessed the safety, tolerability, and plasma-kinetic behavior of 94% pure crystalline epigallocatechin gallate (EGCG) after ten days' repeated dosing in 36 healthy male volunteers. Each of the three treatment groups consisted of 12 subjects; nine of them received oral EGCG in one dose of 200, 400, or 800 mg daily, and three received a placebo. Blood samples for plasma-kinetic EGCG characterization were taken on day 1 and day 10. Kinetic parameters for rate and extent, elimination half-lives, and accumulation factor (R) were determined and compared between day 1 and day 10 for each dosage group. Orally administered EGCG is rapidly absorbed from the gut. Dose linearity was applied for single-dose application (day 1). After repeated dosing (day 10) dose linearity was applied between the 200 mg and 400 mg group. Dose escalation to 800 mg was more than dose-proportional in rate and extent, and statistically different from the 200 mg and 400 mg group. An increase in elimination half-life (t1/2.z) and in the accumulation factor (R) in the 800 mg dosage group indicates dose-dependent saturation of capacity-limited excretion routes or an increase of hepato-duodenal re-circulation. Ten days' repeated administration of oral doses of EGCG of up to 800 mg per day were found to be safe and very well tolerated.

Publication types

  • Clinical Trial
  • Randomized Controlled Trial

MeSH terms

  • Adolescent
  • Adult
  • Camellia sinensis / chemistry*
  • Catechin / administration & dosage*
  • Catechin / analogs & derivatives*
  • Catechin / blood
  • Catechin / pharmacokinetics*
  • Double-Blind Method
  • Half-Life
  • Humans
  • Kinetics
  • Male
  • Middle Aged
  • Placebos
  • Plant Leaves / chemistry*


  • Placebos
  • Catechin
  • epigallocatechin gallate