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How Products were Selected:

Products tested to represent those popular among readers of Consumerlab.com and commonly available nationally in the U.S. ConsumerLab.com purchased products on the open market through retail stores, on-line retailers, and direct sales companies. Products were not accepted directly from manufacturers.

Testing Methods:

Green tea (Camellia sinensis L.) products were tested in one or more independent laboratories for the following:
  1. Total catechins (the sum of epigallocatechin, catechin, epicatechin, epigallocatechin-3-gallate, gallocatechin gallate, epicatechin-3-gallate, catechin gallate and gallocatechin) by high performance liquid chromatography (HPLC).*
  2. Caffeine by HPLC.*
  3. Quantitative analyses for lead, arsenic, and cadmium performed using Inductively Coupled Plasma-Mass Spectroscopy (ICP-MS) for products containing whole herbs and/or more than 250 mg of minerals per daily dose.
  4. Disintegration time of tablets (excluding chewable, sublingual and time-release formulations) using United States Pharmacopeia (USP) <2040> methodology for the disintegration of Dietary Supplements.
  5. Disintegration time of enteric coated, time-release, and sustained release tablet, caplet and softgel formulations utilizing USP <2040> methodology for delayed-release (enteric-coated) tablets.
* Total catechins, caffeine, lead, cadmium and arsenic levels were also analyzed in the liquid of brewable teas after brewing. Teas were brewed using the following procedure: Boil 250mL DI water, remove from heat add 1 tea bag steep for 3 mins with slow stirring remove bag let cool. Transfer a portion to an injection vial and inject, without filtration or centrifugation. Transfer another portion to a separate vial for lead, cadmium and arsenic analysis. Results for brewable teas are reported per serving, adjusted to actual amounts of tea leaf in products.

Testing was performed by one or more independent laboratories. Any product that did not initially pass testing (as defined below) was sent to another independent laboratory to repeat testing for the criterion on which it did not pass.

ConsumerLab.com may modify or use other appropriate test methods if necessary to test special product formulations.

Identities of products were not disclosed to laboratories performing the testing.

Passing Score:*

To "Pass", a product had to meet all of the following requirements:
  1. Catechins: Contain a minimum of 100% and no more than 135% of label claim for total catechins or individual specific catechins (e.g. epigallocatechin gallate (EGCG)). Supplements containing green tea extracts with no total catechin or specific catechin label claim should have no less than 10% total catechins (%wt/wt). Supplements containing non-extracts of green tea with no total catechin or specific catechin label claim should have no less than 4% total catechins (%wt/wt). All green tea products must provide at least 20 mg EGCG per serving (lower amounts suggest questionable therapeutic value and/or quality).
  2. Caffeine: Contain within 20% of label claim for caffeine, except that products claiming less than 10 mg of caffeine must contain no more than 2 mg above label claim. "Decaffeinated" products must contain no more than 0.4% wt/wt caffeine on a dry weight basis (Canadian regulation), i.e., no more than 10 mg per 2.5 grams of tea leaf or tea powder. "Caffeine free" products must have no detectable caffeine. For brewable teas, amounts of caffeine will be determined in the brewed tea.
  3. Heavy Metals: Products containing whole herbs and/or more than 250 mg of mineral per daily dose must not exceed the following limits:
    Lead:
    • Products marketed for use by children may not exceed the State of California's Prop 65 limits for lead in dietary supplements of 0.5 mcg per recommended daily serving with an additional allowance of 0.8 mcg if the product contains more than 1,000 mg/day of calcium.
    • Supplements and matcha powders with single serving weights of less than 5 grams which are not marketed for use by children, may not exceed the State of California's Prop 65 limits for lead in dietary supplements of 0.5 mcg per recommended daily serving (above which a warning regarding reproductive harm, birth defects, or cancer risks is required in California) with an additional allowance of 0.4 mcg if containing 250-999 mg/day of any combination of elemental calcium, magnesium and potassium or 0.8 mcg if containing more than 1,000 mg/day of any combination of these minerals. An additional allowance of 0.5 mcg is provided if containing 250 to 999 mg/day of whole herb (not extract). However, total lead allowance will not exceed 2 mcg per day.
    • Products with single serving weights of 5 grams or more which are not marketed for children may not exceed 2.5 mcg per serving nor 4.0 mcg per daily serving.
    • In beverages and brewable teas (liquid portion). Lead must not exceed 1 mcg per suggested serving. (References: California Prop 65 limits for supplements (above), California Public Health Goals for Chemicals in Drinking Water of 0.5 mcg and 1.5 mcg lead per 240 mL (approx. 1 cup), respectively, as a neurobehavioral toxin and a carcinogen; U.S. EPA Maximum Contaminant Level Goal is zero for lead in drinking water but action level is 3.75 mcg per 250 mL.)
    Arsenic:
    • Contain less than 10 micrograms of total arsenic per daily serving (based on Canada‚Äôs limit per daily serving of a natural health product, and U.S. EPA and state of New Jersey limit in 1 liter of water). Products found to exceed this amount were tested for inorganic arsenic and must not contain more than 2.1 micrograms of inorganic arsenic per daily serving (Canada's additional limit in natural health products).
    Cadmium:
    • If marketed for use by children, may not exceed 3.0 micrograms of cadmium per recommended daily serving (based on Canada's limit for a child weighing 75 lbs.). If not marketed for use by children, may not exceed 4.1 micrograms of cadmium per recommended daily serving (above which California's Prop 65 law requires a "reproductive harm" warning due to developmental toxicity and male reproductive harm.
    Mercury:
    • May not exceed 2 micrograms of inorganic mercury per daily serving (based on EPA limit for mercury in 1 liter of water).
  4. If applicable to the product, must meet recommended USP <2040> parameters for disintegration of dietary supplements (excluding capsule, chewable, sublingual and time-release products).
  5. Enteric coated, time-release, and sustained release tablet, caplet and softgel formulations must meet recommended USP <2040> parameters for delayed-release (enteric-coated) tablets by visual inspection.
  6. Be in compliance with l FDA labeling requirements.
A "Pass" was based on meeting the above criteria from either one or more rounds of testing.

* Passing scores allow for specific margins of technical error associated with each analysis. ConsumerLab.com reserves the right to disqualify a product at any time from passing its testing if it considers such product to display unacceptable variation, represent a safety risk or to provide misleading or inaccurate information in its labeling.

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