# Does green tea extract help with fat loss?

Source: https://www.healthnews24.co.za/answers/does-green-tea-extract-help-fat-loss/
Publisher: Healthnews24 (South Africa's supplement answer desk)
Updated: 2026-10-27

> Barely. A Cochrane review of 18 trials in 1 945 adults found green tea produced a weight change too small to matter, about 0.04 kg in the pooled non-Japanese trials. High-dose extracts also carry a liver risk: European regulators link 800 mg or more of EGCG a day from supplements to raised liver enzymes. In South Africa, skip concentrated extracts.

Key facts:
- Cochrane review: 18 trials, 1 945 adults, 12–13 weeks; pooled non-Japanese trials showed -0.04 kg versus control, judged not clinically important.
- EFSA (2018): 800 mg or more of EGCG a day from supplements is linked to raised liver enzymes.
- Duiven 2021: 38% of 66 Dutch web-shop supplements marketed for fat loss, muscle, energy or hormones contained undeclared doping substances.
- AIS places stimulant fat-loss ingredients (synephrine, DMAA, DMBA) in Group D: banned or high contamination risk.

## What does the research show on green tea and weight?

Green tea contains catechins (mainly EGCG) and caffeine, both of which can nudge energy expenditure slightly in laboratory studies. Real-world trials are less impressive. The Cochrane review of green tea for weight loss and maintenance included 15 weight-loss and 3 weight-maintenance studies, with 1 945 adults completing trials of 12 to 13 weeks. Six studies outside Japan gave a mean difference of only -0.04 kg versus control. Eight Japanese studies reported losses from 0.2 to 3.5 kg but could not be pooled. The reviewers judged the effect too small to be clinically important, and green tea did not help people keep weight off.

We rate the evidence for fat loss as **weak**. Our evidence library places fat burners and thermogenics in the weak category: caffeine and catechins modestly raise energy expenditure, but real-world fat loss is small compared with diet.

## Is green tea extract safe?

Drinking green tea is generally safe. Concentrated extracts are different:

- The European Food Safety Authority (EFSA, 2018) found intakes of 800 mg or more of EGCG a day from supplements were linked to raised liver enzymes (transaminases). Keep supplemental EGCG well below that.
- The UK Committee on Toxicity (2024) published a statement on liver toxicity of green tea catechins, reinforcing that concern.
- Extracts are often taken on an empty stomach, which can increase concentrations in the blood. Read the label for EGCG per capsule, not "extract" weight.
- Many South African fat-burner capsules combine green tea with caffeine and other stimulants, which adds heart-rate, anxiety and sleep effects ([are fat burners safe](/answers/are-fat-burners-safe-south-africa/)).

Stop and see a doctor if you notice yellowing of the skin or eyes, dark urine, upper-right abdominal pain, or unusual fatigue. People with liver disease, pregnant or breastfeeding women, under-18s, and anyone taking medicines should avoid green tea extract unless a doctor agrees.

## What about drug-tested athletes?

Green tea itself is not prohibited, but multi-ingredient fat burners are among the highest-risk products. The Australian Institute of Sport places stimulant fat-loss ingredients such as synephrine, DMAA and DMBA in Group D (banned or high contamination risk), and a 2021 Dutch study found 38% of 66 products marketed for fat loss, muscle gain, energy or hormone modulation contained undeclared doping substances. SAIDS lists fat burners as high-risk ([failed drug tests and supplements](/answers/can-supplements-cause-failed-drug-test-south-africa-rugby/)).

## What is a better use of your money?

If you like green tea, drink two to four cups a day. That gives modest caffeine and polyphenols with a far lower catechin load than extracts. For fat loss, spend on protein, a pair of dumbbells or a gym membership before spending on thermogenics. See [do fat burners work in South Africa](/answers/do-fat-burners-work-south-africa/) and [caffeine and fat loss](/answers/caffeine-and-fat-loss-thermogenics/).

## Sources

- [Cochrane review: Green tea for weight loss and weight maintenance in overweight or obese adults](https://www.cochrane.org/CD008650/green-tea-for-weight-loss-and-weight-maintenance-in-overweight-or-obese-adults)
- [NutraIngredients (Apr 2018): EFSA safety assessment on green tea catechins (EGCG) and liver effects](https://www.nutraingredients.com/Article/2018/04/19/EGCG-warning-EFSA-safety-assessment-suggests-green-tea-supplements-should-come-with-warning)
- [UK Committee on Toxicity (2024): Statement on the hepatotoxicity of green tea catechins (lay summary)](https://cot.food.gov.uk/sites/default/files/2024-11/COT%2008.2024%20-%20Statement%20on%20the%20hepatotoxicity%20of%20green%20tea%20catechins_Lay%20summary.pdf)
- [Duiven E et al. (2021) Undeclared doping substances are highly prevalent in commercial sports nutrition supplements. J Sports Sci Med 20:328](https://jssm.org/jssm-20-328.xml-abst)
- [Australian Institute of Sport Supplement Framework: Group D](https://www.ausport.gov.au/ais/nutrition/supplements/group_d)