Green tea is taken by mouth to improve mental alertness and thinking.
It is also taken by mouth for depression, non-alcoholicfatty liver disease (NAFLD), inflammatory bowel disease (ulcerative colitis or Crohn's disease), weight loss and to treat stomach disorders, vomiting, diarrhea, headaches, and bone loss (osteoporosis).
Green tea is also taken by mouth for Parkinson's disease, diseases of the heart and blood vessels, diabetes, low blood pressure, chronic fatigue syndrome (CFS), dental cavities (caries), kidney stones, and skin damage.
Instead of drinking green tea, some people apply green tea bags to their skin to soothe sunburn and prevent skin cancer due to sun exposure. Green tea bags are also used to decrease puffiness under the eyes, as a compress for tired eyes or headache, and to stop gums from bleeding after a tooth is pulled. A green tea footbath is used for athlete's foot.
Some people gargle with green tea to prevent colds and flu. Green tea extract is also used in mouthwash to reduce pain after tooth removal. Green tea in candy is used for gum disease.
Green tea is used in an ointment for genital warts.