How much green tea extract should you take a day?

There's no government-set recommended dose for green tea extract, unlike vitamins and minerals with an official intake range. What exists instead is a wide scatter of amounts: a 2018 EFSA scientific opinion found commercial supplements deliver EGCG doses anywhere from 5 mg to 1,000 mg a day, and found trial evidence that doses at or above 800 mg a day raised liver enzymes.

What the label numbers mean

Most green tea extract labels state either a total catechin/polyphenol amount or a specific milligram figure for EGCG, the catechin most consistently measured in research. A 2018 EFSA scientific opinion reviewing the full published evidence found that supplements on the market span a wide range — from 5 mg to 1,000 mg of EGCG a day — with no single figure representing a typical or "correct" amount (PMID 32625874). If a label states total catechins or total polyphenols instead of EGCG specifically, that number will usually be higher than the EGCG content alone, since EGCG is one catechin among several.

What trials have actually tested

A 2005 crossover trial gave 30 healthy adults a single dose of a decaffeinated, standardized green tea catechin extract at 400, 800, or 1,200 mg based on EGCG content, either fasting or with a light meal. All three doses were generally well tolerated; mild, transient nausea showed up most often at the highest dose (1,200 mg EGCG) taken on an empty stomach (PMID 15958649). That trial also found taking the extract fasting more than tripled peak blood EGCG levels compared with taking it with food — more on what that means for timing in when is the best time to take green tea extract?.

Caffeine content, separately from catechin content

A green tea extract's caffeine content is a different number from its catechin content, and it isn't always stated as clearly on the label. A 2007 USDA laboratory analysis of 53 commercial caffeine-containing supplements — a set that included products built around green tea extract, guarana, yerba mate, and kola nut — found actual per-day caffeine amounts ranging from 1 mg to 829 mg across products, though most brands' measured caffeine was reasonably close to the labeled amount (PMID 17676317). If a product doesn't specifically say "decaffeinated," it's reasonable to assume it carries some caffeine, and the exact amount is a per-label question rather than one this page can answer generally.

Is there a maximum, or a dose that's too much?

Green tea extract doesn't have a formally established upper intake level the way some vitamins and minerals do. What exists is a dose threshold tied specifically to liver-enzyme changes: the same 2018 EFSA opinion concluded that interventional clinical trials showed EGCG intake at or above 800 mg a day from a supplement produced a statistically significant rise in liver enzymes compared with control (PMID 32625874). Separately, a 2020 United States Pharmacopeia expert panel review of published liver-injury case reports found they span EGCG intakes from about 140 mg to 1,000 mg a day, with wide variation between individuals in how susceptible they appear to be — meaning some people reported problems well below the 800 mg EFSA threshold, and most people who take much more never report one (PMID 32140423). Neither finding sets a hard line under which a dose is guaranteed safe; see green tea extract side effects and who should not take green tea extract? for more on what that case-report data covers.

Questions people ask

Is 500 mg of green tea extract too much?

500 mg sits below the 800 mg/day EGCG threshold that EFSA's review linked to liver-enzyme changes in trials, assuming the label is stating EGCG rather than total catechins. It's also within the case-report range USP's review identified (140-1,000 mg/day), so "below a threshold" isn't the same as "risk-free" for every individual.

Is 800 mg of green tea extract too much?

800 mg of EGCG a day is the specific dose EFSA's 2018 opinion identified as the point where interventional trials showed a statistically significant liver-enzyme increase. That doesn't mean everyone taking 800 mg will have a problem, but it is the figure regulators have flagged.

How many mg of green tea extract per day is normal?

There's no single normal amount — commercial products range from 5 mg to 1,000 mg of EGCG a day. Following the specific product's label directions, and not exceeding 800 mg of EGCG a day without a reason to, is a more useful anchor than a single "normal" number.

How much caffeine does green tea extract have?

It depends entirely on the product. A 2007 lab analysis of caffeine-containing supplements found amounts from 1 mg to 829 mg a day across the products tested, and a green tea extract labeled "decaffeinated" should have little to none. Check the specific label; there's no standard figure across brands.

How much green tea extract is safe per day?

No amount has been declared universally safe, but the clearest regulatory reference point is EFSA's 800 mg EGCG/day threshold for liver-enzyme changes in trials. See who should not take green tea extract? for who should be more cautious at any dose.

Related reading: what is green tea extract? A plain guide, when is the best time to take green tea extract?, and green tea extract side effects.