How Products were Selected: Products selected 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 Method: Vitamin C products were each tested for their amount of vitamin C utilizing a HPLC (High Performance Liquid Chromatography) or CE (capillary electrophoresis).
Disintegration of non-chewable, non-capsule, non-enteric coated and non-time release formulations was analyzed by ConsumerLab.com utilizing USP (United States Pharmacopeia) <2040> methodology.
Products failing to meet any Passing Score were re-tested in a second independent laboratory using similar methods and instrumentation.
ConsumerLab.com may modify or use other appropriate test methods if necessary to test special product formulations.
Passing Score: * To achieve a "Pass" in the testing, a product had to:
Contain a minimum of 100% of its labeled amount of vitamin C and not exceed 120% of this amount.
Meet recommended USP parameters for disintegration for dietary supplements (excluding capsule, enteric coated, chewable and time-release products).
A "Pass" was based on meeting the above criteria in either the first or second 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 present a safety risk or to provide misleading or inaccurate information in its labeling.