Green tea is safe for most adults when used in moderate amounts. However, for use beyond 12 weeks, consult your health care provider.
Green tea and green tea extractextractto get, separate, or isolate a desired active ingredients contain caffeine. Caffeine can cause insomnia, anxiety, irritability, upset stomach, nausea, diarrhea, or frequent urination in some people. Caffeine can also raise blood pressure, and in very high doses, it can cause seizures, delirium, or irregular heart rhythms.
Green tea contains small amounts of vitamin K, which can make anticoagulant drugs, such as warfarin, less effective.
Tell your health care providers about any herb or dietary supplement you are using, including green tea. This helps to ensure safe and coordinated care.
Consult a health care provider before using green tea if:
Before taking any new medications, including natural health products, speak to your physician, pharmacist, or other health care provider. Tell your health care provider about any natural health products you may be taking.