Green Tea Extract
Green tea extract concentrates constituents of Camellia sinensis leaves, mainly catechins and, unless decaffeinated, caffeine.
Also listed as Camellia Sinensis, GTE, Green Tea Catechins, Green Tea Leaf Extract
What it is studied for
The strongest rated effects first. Bars show the size of the effect, the letter grades the evidence, and each rating lists the studies behind it.
What is inside green tea extract?
Green tea comes from Camellia sinensis leaves and contains catechins and caffeine. Extracts concentrate constituents of those leaves. The research question depends on what is in the preparation: tea, a caffeine-containing extract and a decaffeinated product are not automatically interchangeable. 1 2
Why study catechins and caffeine together?
Researchers have proposed that catechins and caffeine could work together to increase energy expenditure and fat oxidation. NIH’s review describes that rationale, but also the small and inconsistent weight changes in human trials. A plausible mechanism does not tell us whether the difference will matter on a bathroom scale. 2
Key studies
The most recent publications linked to Green Tea Extract's ratings.
Why people take it
SuppCo community snapshot, 2026-09-28. Reasons for use are not evidence that it works.
Questions people ask
Is 500 mg of extract the same as 500 mg EGCG?
No. EU labeling distinguishes extract portions from their EGCG content; the EGCG amount is the relevant figure for the restriction. 3
Is a dose below 800 mg EGCG definitely safe?
No. EFSA could not establish a safe supplemental EGCG dose. 4
Does decaffeinated extract reliably cause weight loss?
A year-long trial summarized by NIH found no overall weight, BMI or waist benefit from decaffeinated extract in postmenopausal women with overweight or obesity. 2
Can it replace cholesterol treatment?
The lipid trials measured a small average change in blood values. They do not establish that substituting an extract for prescribed treatment prevents cardiovascular events. 5
EGCG
Green Coffee Extract