Heart Health

About This Health Centre

Heart disease and stroke are the leading causes of death among Canadians - and many people don't know they're at risk. But it's not hard to stay healthy and fit if you know what to do. Learn about how to stay healthy, recognize risk factors, and understand and deal with cardiovascular problems when they occur. For additional health information, please talk to your Costco Pharmacist.

Heart Health

Green Tea

Green Tea

General Information

All types of tea (green, black, and oolong) are produced from an evergreen shrub called Camellia sinensis using different methods. Camellia sinensis is native to China, Japan, and countries in North Africa and Middle East. Fresh leaves from the Camellia sinensis plant are steamed to produce green tea. People commonly consume green tea as a beverage or as an extractextractto get, separate, or isolate a desired active ingredient.

Common Name(s)

green tea, Chinese tea, Japanese tea

Scientific Name(s)

Camellia sinensis L. (Family: Theaceae); synonym: Thea sinensis, Camellia thea, Camellia theifera, Thea bohea, Thea viridis

How is this product usually used?

Green tea is usually brewed and drunk as a beverage. Green tea extractextractto get, separate, or isolate a desired active ingredients can be taken in capsules and are sometimes used in skin products.

Green tea extract:

What is this product used for?

Green tea extractextractto get, separate, or isolate a desired active ingredient is a source of antioxidantantioxidanta chemical substance that prevents cellular damage from free radicalss for the maintenance of good health. It is used as an adjunct to a weight management program in combination with healthy diet and regular exercise.

Green tea and green tea extracts, such as its component EGCG, have been used to prevent and treat a variety of cancers, including breast, stomach, and skin cancers.

Green tea and green tea extracts have also been used for improving mental alertness,  lowering cholesterol levels, and protecting skin from sun damage.

Your health care provider may have recommended this product for other conditions. Contact a health care provider if you have questions.

What else should I be aware of?

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.


National Center for Complementary and Alternative Medicine. Herbs at a Glance. Green Tea. http://nccam.nih.gov/health/greentea, accessed June 13, 2007.

Health Canada. Drugs & Health Products. Monograph. http://webprod.hc-sc.gc.ca/nhpid-bdipsn/atReq.do?atid=greentea_thevert&lang=eng, accessed April 25 2016. Last modified April 18 2016.


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