On November 15, 2017, Health Canada (the Canadian equivalent of the FDA) recommended stronger warning statements about the risk of liver toxicity on labels of supplements containing green tea extract sold in Canada. 

The new recommended statements include:

• "If you have a liver disorder, consult a health care practitioner prior to use. Stop use if you develop symptoms of liver trouble such as yellowing of the skin/eyes (jaundice), stomach pain, dark urine, sweating, nausea, unusual tiredness and/or loss of appetite and consult a health care practitioner"; and 



• "Rare, unpredictable cases of liver injury associated with green tea extract-containing products have been reported (in Canada and internationally)

Health Canada also advised that green tea extract products be used only by adults.

Liver toxicity associated with the use of green tea extract products has been reported in both the U.S. and Canada, as well as in other countries. Health Canada's recent safety review of green tea extract products noted that the United States Pharmacopeia's (USP) 2008 review cited 34 cases of liver injury associated with the use of green tea extract, and another 19 cases reported internationally since 2008. Health Canada received 11 reports of suspected livery injury associated with the use of green tea extract between 2006 and 2016. Most cases resolved with stopping use of the product and medical treatment; however, in one case, a more serious disease (chronic liver fibrosis) developed and in two cases, a liver transplant was required. 

One of the most recent cases reported in Canada involved a 17 year old woman who developed liver and kidney injury after using Green Tea Triple Fat Burner, a licensed natural product sold in Canada that contains green tea extract, bitter orange, caffeine, and various vitamins. She experienced acute abdominal pain, nausea and excessive vomiting. Her levels of the liver enzyme alanine aminotransferase (ALT) were found to be 64 times the upper limit of normal, and creatinine levels (a measure of kidney function) were found to be 10 times the upper limit of normal. She was treated with dialysis and medication, and her liver and kidney function returned to normal.

In 2007, the USP proposed a warning label for green tea extracts sold in the U.S. but the proposal was cancelled two years later. Both the proposed USP warning and Health Canada's Green Tea monograph recommend that green tea extract products be taken with food. Liver toxicity associated green tea beverages appears to be much less common than with concentrated extracts sold as supplements, although rare cases of liver toxicity associated with beverages have been reported.

For more information about green tea exact and liver toxicity, see the "Concerns and Cautions" section of ConsumerLab.com's Green Tea Review. 

See related recalls and warnings:

Liver Injuries Linked With Dietary Supplement Use on the Rise

Green Tea from Tea Bags Linked to Acute Hepatitis

To read Health Canada's complete summary safety review of green tea extract products, use the link below.