1) Skin Aging and UV Damage
The topical application of creams with GREEN TEA 3505 extract improved skin elasticity, reduced wrinkles, and protected from the harmful effects of UV radiation (aging, burns, immunosuppression) in 5 clinical trials on 87 people. However, another trial on 40 women found it ineffective.

The results of trials using oral green tea polyphenols are mixed. These compounds had similar effects to topical preparations in 4 clinical trials on over 150 people but were ineffective in 3 trials on over 150 people.

Due to the mixed results, it’s difficult to draw conclusions on the effects of oral and topical green tea on skin aging. Further clinical research is needed to shed some light on this potential use.

2) Acne
In 2 clinical trials on 99 people with acne, drinking decaffeinated green tea daily for 4 weeks reduced inflammatory lesions on the nose, chin, and around the mouth.

Cell-based studies found that epigallocatechin gallate can block fat secretion in the skin and inhibit a microbe that causes acne (Propionibacterium acnes).

Although the results are promising, the evidence is insufficient to claim for certain that green tea helps with acne. More clinical trials on larger populations are warranted.

3) Infections
In a clinical trial on almost 400 people, topical green tea resolved skin MRSA infections in all cases.

In a clinical trial on 200 healthcare workers for the elderly, taking green tea catechins (378 mg/day) and theanine (210 mg/day) reduced the incidence of common flu. However, gargling with green tea was ineffective for flu prevention in another trial on over 750 children.

Green tea was also of little against upper respiratory infections in a clinical trial on almost 300 people.

In test tubes, green tea and its components inhibited several infectious bacteria.

A few clinical trials with mixed results and some cell-based studies cannot be considered sufficient evidence that green tea helps fight infections. Larger, more robust clinical trials are needed to back this potential benefit.

4) Bone Loss
In a clinical trial on 171 postmenopausal women with low bone density, an intervention with green tea polyphenols and tai chi improved bone formation biomarkers and muscle strength, while reducing oxidative damage that may worsen bone loss. The intervention was safe and well-tolerated.

However, another study on almost 1,000 postmenopausal women given green tea extract for 12 months found it ineffective to improve bone mineral density .

Epigallocatechin gallate promoted bone development in cell-based studies.

Two studies with opposite results are clearly insufficient to support this potential health benefit. More research is needed to shed some light on it.

5) Liver Health
In a clinical trial on 17 people with non-alcoholic fatty liver disease, high-catechin green tea reduced fat content, inflammation, and oxidative damage in the liver.

Similarly, it reversed mild fatty liver in another trial on 60 people with high blood cholesterol.

However, high doses (1315 mg catechins/day) for 12 months were toxic to the liver in a study on over 1,000 women.

Two small clinical trials cannot be considered sufficient evidence that green tea improves fatty liver disease. Additionally, high catechin doses have been clearly associated with liver damage.

6) Hair Loss
The polyphenols in green tea stimulated human hair growth in test tubes and on the scalps of 2 volunteers. Further research should replicate this preliminary finding.