How Products were Selected:
Products were selected to represent those commonly sold and/or available nationally in the U.S. ConsumerLab.com purchased products on the open market through retail stores, on-line retailers, and direct sales or multi-level marketing companies. Products were not accepted directly from manufacturers.
Ashwagandha products were tested in one or more independent laboratories for the following:
- Total withanoside and withanolide content by HPLC (High Performance Liquid Chromatography).
- Quantitative analyses for lead, cadmium and arsenic by Inductively Coupled Plasma-Mass Spectroscopy (ICP-MS) for products containing whole herbs and/or more than 250 mg of minerals per daily dose.
- Non-chewable, non-capsule, and non-time-release formulations were analyzed for disintegration utilizing United States Pharmacopeia (USP) <2040> recommendations entitled "Disintegration and Dissolution of Nutritional Supplements."
Any product not passing testing was sent to another independent laboratory to repeat testing for criterion on which it did not pass.
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.
To achieve a "Pass" in testing, a product had to meet the following criteria:
- 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, withastramonolide, withanolide A, withanone and withanolide B (USP-40). Root/rhizome powders are expected to contain a minimum of 0.3% (wt./wt.) total withanolides and withanosides (USP-40) and extracts expected to contain a minimum of 1.5% (wt./wt.) total withanolides and withanosides (CL minimum based on Industry Standard). 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 more than 250 mg of mineral per daily dose must not exceed the following limits:
- 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 of lead per 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 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 with an additional allowance of 0.4 mcg if containing 250-999 mg/day of elemental calcium, magnesium and potassium, 0.8 mcg if containing more than 1,000 mg/day of any combination of these minerals. An additional 0.5 mcg is provided if containing 250-999 mg/day of whole herb (not extract) ingredient or 1.0 mcg for products containing 1000 mg/day or more of whole herb (not extract). However, total lead allowance will not exceed 2 mcg.
- 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.
- 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 (based on the State of California's Prop 65 limit).
- Contain less than 10 micrograms of total arsenic and no more than 5 micrograms of inorganic arsenic per daily serving (EPA and state of New Jersey limits - based on 1 liter of water).
- If applicable to the product, it must meet recommended USP <2040> parameters of disintegration for dietary supplements (excluding capsule, chewable and time-release products).
- Be in compliance with FDA labeling requirements
** Based on State of California's Prop 65 limits. California requires supplements exceeding this limit to bear a warning label.