Epigallocatechin Gallate (EGCG): A Comprehensive Monograph on its Pharmacology, Clinical Utility, and Safety Profile

Executive Summary

Epigallocatechin gallate (EGCG) stands as the most abundant and biologically active catechin within green tea (Camellia sinensis), a natural product that has garnered immense scientific and public interest for its potential health benefits. Preclinical research has extensively documented its potent antioxidant, anti-inflammatory, antineoplastic, and neuroprotective properties, positioning it as a highly promising therapeutic agent for a wide spectrum of chronic and infectious diseases. However, the trajectory from promising preclinical compound to effective clinical therapeutic is fraught with significant challenges, and EGCG serves as a paradigmatic example of this difficult transition. The central obstacle that defines and complicates its clinical development is its exceptionally poor oral bioavailability. This pharmacokinetic limitation necessitates the administration of high oral doses to achieve potentially therapeutic systemic concentrations. This requirement, in turn, creates a profound efficacy-safety dilemma, as these high doses—particularly those at or above 800 mg per day—are directly associated with a statistically significant risk of dose-dependent hepatotoxicity.