The CFR (Code of Federal Regulations) 21 Part 111 "cGMP (current Good Manufacturing Practice) in Manufacturing, Packaging, Labeling, or Holding Operations for Dietary Supplement" by the U.S. Food and Drug Administration (hereinafter referred to as "FDA") came into effect on August 24, 2007. The regulation states that dietary supplement manufacturers must perform one or more tests to ensure content uniformity in the supplement, specifi cally, purity, composition and content quantitation. The regulation is also required to apply to supplements imported into the United States from overseas. Dates have been set for dietary supplement manufacturers, based on company size, to comply with the regulation. Companies with 500 employees or more were obliged to put this regulation into effect starting June 24, 2008. Companies with 20 to 499 employees started on June 24, 2009. Those with less than 20 employees started on June 24, 2010. This application note introduces examples of analysis of dietary supplements using analysis methods that conform with those of the United States Pharmacopeia (hereinafter referred to as "USP").