How Products were Selected:
Products were selected to represent those commonly available nationally in the U.S. and popular among readers of ConsumerLab.com. 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:
Ashwagandha products were tested in one or more independent laboratories for the following:- Total withanoside and withanolide content by High Performance Liquid Chromatography (HPLC) (USP-DSC 2023).
- Quantitative analyses for lead, arsenic, cadmium and mercury by Inductively Coupled Plasma-Mass Spectroscopy (ICP-MS) for products containing whole herbs and/or 250 mg of minerals or more per daily dose.
- Disintegration of tablets (excluding chewable, sublingual, and time-release formulations) utilizing United States Pharmacopeia (USP) <2040> recommendations entitled "Disintegration and Dissolution of Nutritional Supplements."
- 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."
ConsumerLab.com may modify or use other appropriate test methods if necessary to test special product formulations.
The identities of the products were not disclosed to the laboratories performing the testing.
Passing Score:*
To be "Approved" for quality, a product had to meet the following requirements:- Contain at least 100% and no more than 150% of its claimed or minimum expected amount of total withanolide (aglycones) and withanosides (withanolide glycosides). Total withanolides and withanosides are calculated as the sum of withanoside IV, withanoside V, withanoside VI, withaferin A, 12-deoxywithastramonolide, withanolide A, withanone and withanolide B (USP-DSC 2023). Root/rhizome powders are expected to contain a minimum of 0.3% (wt./wt.) total withanolides and withanosides (USP-DSC 2023) and extracts expected to contain a minimum of 1.5% (wt./wt.) total withanolides and withanosides (CL minimum based on Industry Standard, which is lower than the 2.5% USP minimum). The minimum will be applied if the product does not state an amount of total withanolides and withanosides in an Ashwagandha-based ingredient or if the claimed amount is lower than the expected minimum. (Although not a requirement for Pass, any product claiming or providing less than 6 mg of withanolides and withanosides per daily dose will be noted in the Review as providing a "low dose").
- Heavy Metals: Products containing whole herbs and/or 250 mg or more of minerals per daily dose must not exceed the following limits:
Lead:- Products marketed for use by children under 12 years of age 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.
- Products with a single serving weight of less than 5 grams that are not marketed for use by children under 12 years of age, 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 250-999 mg/day of whole herb (not extract) or 1.0 mcg if containing 1000 mg/day or more of whole herb (not extract). However, total lead allowance must not exceed 2 mcg per daily serving.
- Products with single serving weights of 5 grams or more that are not marketed for children under 12 years of age may not exceed 2.5 mcg per serving nor 4.0 mcg per daily serving.
- Contain less than 10 micrograms of total arsenic per daily serving (based on Canada’s 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).
- If marketed for use by children under 12 years of age, may not exceed 3.0 micrograms of cadmium per recommended daily serving (based on Canada's limit for a child weighing 75lbs). If not marketed for use by children under 12 years of age, 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.
- May not exceed 2 micrograms of inorganic mercury per daily serving (based on EPA limit for mercury in 1 liter of water).
- If applicable to the product, meet recommended USP <2040> parameters of disintegration for dietary supplement tablets (excluding sublingual, chewable and time-release products).
- 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.
- Meet FDA labeling requirements.
* 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 in quality, present a safety risk or to provide misleading or inaccurate information in its labeling.
