What it is
Green tea extract concentrates Camellia sinensis catechins, often including EGCG, and can deliver far more catechin than brewed tea.
Core function and why it is studied
Its composition or proposed mechanism makes cardiovascular function, antioxidant pathways logical research areas. Studies therefore examine metabolic, lipid, and antioxidant measures. That biological connection explains why it is studied; it does not by itself establish a meaningful benefit.
What the evidence means
Human studies and reviews report variable results. Differences in preparation, dose, duration, population, and outcome selection limit broad conclusions.
How to compare products
Compare species, plant part, extract ratio, solvent, standardized constituents, serving amount, and contaminant testing.