Health Canada takes steps to help Canadians avoid rare risk of liver injury from use of green tea extract health products

Starting date:
November 14, 2017
Type of communication:
Information Update
Subcategory:
Natural health products
Source of recall:
Health Canada
Issue:
Important Safety Information
Audience:
General Public
Identification number:
RA-65114

OTTAWA – Health Canada has completed a safety review of green tea extract in natural health products and, as a result, is strengthening the warnings on labels of these products to help reduce the risk of liver injury.

Green tea extract is an herbal ingredient found in natural health products promoted for a range of uses, including weight management and as a source of antioxidants. It is sold in various forms as capsules, tablets, powders and liquids. The vast majority of products are authorized for adult use only (18 years of age and older), including those authorized for weight management.

Green tea in any form, including as beverages, foods and an extract in natural health products, is considered generally safe for the majority of consumers. The liver-related adverse reactions with green tea extract in natural health products, while potentially serious, are rare. The risk of liver-related injury is already included in the approved Health Canada label, or monograph. Since it was developed in 2008, Health Canada’s monograph for Green Tea Extracts has included a warning advising consumers to consult a healthcare practitioner before using the product if they have a liver disorder, or if they develop symptoms of liver trouble. It also advises that these products should be taken with food to help reduce the risk of side effects, including liver injury. In most cases, the liver-related side effects are reversible upon stopping use of the product and with medical attention.

Health Canada undertook the safety review in light of continuing reports worldwide of cases of serious liver injury, including a recent report in Canada. The purpose of the review was to further clarify the risk and identify whether added safety measures might be needed. Health Canada has concluded that the available evidence confirms a link between green tea extract and rare liver-related adverse reactions. What remains unclear from the evidence is why some people may be more susceptible than others to liver injury.

Because of the uncertainty of this potential risk, Health Canada is taking additional steps to help improve the safe use of green tea extract natural health products. The Department:

  • is asking companies to update all affected natural health product labels with strengthened warnings to advise that:
    • rare but serious cases of liver injury have been reported with green tea extract use
    • consumers should stop using these products if symptoms or signs of potential liver injury appear (the revised warnings appear in the table below).
  • has updated the Green Tea Extracts monograph, which applies to certain products, to incorporate the revised warnings.
  • is requesting, as a precautionary measure, that product licence holders of natural health products containing green tea extract as a medicinal ingredient and that are intended for children and adolescents:
    • either remove the green tea extract from such products, or
    • revise the label to indicate that the product is only for adults (18 years and older).
Current and strengthened warnings
Current warnings Strengthened warnings

Since 2008, the labels of natural health products that contain green tea extract have typically included:

  • a statement about the risk of liver injury: “consult a healthcare practitioner prior to use if you have a liver disorder or if you develop symptoms of liver trouble (such as abdominal pain, dark urine or jaundice)”
  • a direction to “take with food”

Health Canada is clarifying warnings by requesting product labels to include new text as indicated in bold:

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

Health Canada is also communicating this information directly to health professionals.

What should consumers do?

  • Parents and caregivers should check to make sure that their child is not taking a green tea extract product.
  • If you have a liver disorder, talk to a health care practitioner before using a natural health product that contains green tea extract.
  • Read the ingredients and follow the directions of the health products you use. Keep in mind that using more than one product at a time with similar purposes or ingredients can increase the risk of accidently taking too much of that ingredient.
  • Check whether your natural product contains green tea extract by looking for the common name “Green tea extract” on the package label.
    • Labels may also show the combination of the Latin name "Camillia sinensis" and any of these other common names that indicate that a product may contain green tea extract:
      • "Camellia Sinensis Leaf Extract," "Camellia sinensis," "Camellia sinensis extract," "Tea Extract," "Tea Leaves Extract," "Thea Chinensis Extract," and "Thea sinensis extract."
  • Take any green tea extract natural health product with food and not on an empty stomach.
  • Stop using the product and consult a health care practitioner if you develop any of the following signs, as they may be symptoms of liver trouble: yellowing of the skin or eyes (jaundice), dark urine, sweating, nausea, vomiting, stomach pain, unusual tiredness, or loss of appetite.
  • Report side effects or complaints involving green tea extract products, or any other health product, to Health Canada. These reports are important in helping us to identify and clarify potential safety concerns.

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