1. **Whitening and spot reduction**: Vitamin C in green tea can lighten the melanin in the skin, which can play a role in whitening and reducing the effect of melanin, so that the skin will become more white. At the same time, the tannins in green tea can lighten dark spots and freckles, and are also effective in removing spots and acne.

2. **Antioxidant**: The catechins in green tea have antiseptic and anti-inflammatory effects, which can improve the problem of skin allergies, while the vitamin E in green tea also has an antioxidant effect, which is very effective for skin protection.

3. **Supplementation of water**: Green tea in the tea polyphenols contain hydrophilic genes, can effectively absorb moisture in the air, while green tea in the vitamin B, vitamin E and other ingredients can help the skin to replenish the loss of water.

4. **Anti-inflammatory and calming**: Green tea is cool in nature and contains tea polyphenols that help the skin to fight bacteria, which can assist in avoiding inflammatory damage, cleansing the skin, and has a calming and soothing effect on the skin.

Overall, green tea mask has a variety of effects, however, some people may be allergic to green tea ingredients, so it is recommended to use a small area on the back of the hand before use, to ensure that there is no allergy before applying face. If an allergic reaction occurs, stop using it immediately and seek medical attention.