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HOW PRODUCTS WERE EVALUATED:
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.
Testing Methods:
Products were tested for amount(s) of selected key ingredients: acetyl-L-carnitine, Ginkgo biloba, and huperzine A. Analyses included identification of potential contamination with lead in botanical products. The products were also tested for their ability to disintegrate in solution (excluding capsules, chewable and time-release products).
For each ingredient, the following testing method was employed:
Acetyl-L-carnitine:
- Quantitative analysis of acetyl-l-carnitine by High Performance Liquid Chromatography (HPLC) using Ultra Violet (UV) detection.
Ginkgo:
- Quantitative analysis of bilobalide and ginkgolides (Terpene Lactones) by HPLC using an Evaporative Light Scattering Detector (ELSD) or by a Gas Chromatographic (GC) method.
- Quantitative analysis of flavonol glycosides utilizing a HPLC method with UV detection.
- Analyses for lead were performed using Inductively Coupled Plasma-Mass Spectroscopy (ICP-MS) instrumentation.
Huperzine A:
- Quantitative analysis of (-) huperzine A performed by Capillary Electrophoresis (CE) with UV detection.
- Analyses for lead were performed using an Inductively Coupled Plasma-Mass Spectroscopy (ICP-MS).
Disintegration of non-chewable, non-capsule, non-enteric coated and non-time-release formulations was analyzed utilizing USP (United States Pharmacopeia) <2040> recommendations entitled "Disintegration and Dissolution of Nutritional Supplements."
Analyses were conducted in an independent laboratory to which the brand identities of the products were not disclosed. Any products not passing the initial analyses was retested in a second independent laboratory on at least one of the criteria on which it did not initially pass.
Passing Score: *
To pass testing, a product must meet the following criteria:
Acetyl-L-carnitine
- Contain a minimum of 100% and not exceed 150% of label claim for acetyl-L-carnitine (free base) or acetyl-L-carnitine complexes (e.g. acetyl-l-carnitine hydrochloride).
Ginkgo
- Contain at least 100%, and not more than 150% of the expected amounts of total and individual flavonol glycosides and total terpene lactones based on the claimed amount of Ginkgo biloba leaf extract and the ratios defined below. (Ginkgo leaf products must contain a minimum of 0.8% flavonol glycosides.)
Flavonol Glycosides:
Total flavonol glycosides 22-27% (wt/wt)** (Sum of quercetin, kaempferol and isorhamnetin)
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Quercetin |
minimum 9.5% (wt/wt) |
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Kaempferol |
minimum 10.5% (wt/wt) |
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Isorhamnetin |
minimum 2.0% (wt/wt) |
Terpene Lactones:
Total terpene lactones 5-7% (wt/wt)** (Sum of ginkgolides A,B,C and bilobalide)
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Ginkgolides A, B, C |
minimum 2.8%(wt/wt)** |
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Bilobalide |
minimum 2.6% (wt/wt)** |
**Reference: German Commission E Monograph, American Herbal Pharmacopoeia Monograph
- Not exceed California Prop 65 levels for lead contamination in a recommended daily serving.
Huperzine A
- Contain at least 100% and not more than 150%, of the expected amount of (-) - huperzine A. If product claims to be made from natural source huperzine A (e.g. Huperzia serrata (Thunb. ex Murray) Trevis, toothed club moss) the expected amount of (-) - huperzine A shall be equivalent to the claimed amount of huperzine A. If Product does not claim to be from natural source, or claims to be made from synthetic huperzine A, 50% of the claimed amount of huperzine A shall be expected to be (-) - huperzine A.
- Not exceed California Prop 65 levels for lead contamination in a recommended daily serving.
All Products
- Meet recommended USP parameters for disintegration for nutritional supplements (excluding capsule, chewable and time-release products).
- Meet all FDA labeling requirements.
A product passed if it passed each criterion in any one of the analyses.
* 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 present a safety risk or to provide misleading or inaccurate information in its labeling.
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