The quality of herbal supplements has been the subject of an ongoing investigation initiated earlier this month by the New York Attorney General’s office. Specifically, the Attorney General’s office has conducted DNA tests on samples of herbal supplements sold at GNC, Walgreens, Target and Walmart and concluded that a majority contained none of the active botanical ingredients their labels claim to have and some were even found to have unwanted contaminants.
The supplement industry has strongly questioned the DNA barcoding technology used by the Attorney General’s office as the basis of its conclusions. Many in industry argue that the technology is not robust enough to substantiate the claims of product fraud and insist that their products meet current good manufacturing practices and regulatory expectations. Some even point to their compliance with USP monographs—detailed written standards used to establish the quality of dietary supplements.
For nearly two centuries, the U.S. Pharmacopeial Convention (USP) has been creating quality standards for drugs and their ingredients. Manufacturers that sell drug products and their ingredients in the U.S. must adhere to USP’s standards, which, by law, are enforceable by the U.S. Food and Drug Administration. Regardless of where these products are made in the world, manufacturers must comply.
But when it comes to dietary supplements such as botanicals and their ingredients, the regulatory laws are different than those that govern drugs. Although USP’s standards also include those for dietary supplements, adoption of these standards by manufacturers is voluntary.
In recent weeks, questions have been raised with regard to compliance with USP standards for dietary supplements. It’s important to bring clarity to these issues and provide an accurate explanation as to what “compliance with USP” entails.
- What tests do manufacturers need to meet in order to be in compliance with USP?
A manufacturer must meet all the requirements of tests and specifications in a USP monograph for a single product in order to be considered in compliance.
A monograph is a written standard that establishes public specifications for an article’s quality. A USP monograph—whether for a drug product/ingredient or a dietary supplement—provides the name of that article; its definition; package, storage and labeling requirements; and a list of tests with related analytical procedures and acceptance criteria (usually expressed in percentage ranges or limits) needed to ensure identity, strength, purity and the absence of or control for contaminants.
- Some manufacturers follow standards articulated in USP’s general chapters. What does this mean with regard to compliance?
USP monographs are published in the U.S. Pharmacopeia—National Formulary (USP-NF). This publication also includes general chapters, which may include procedures and tests and may apply to more than one monograph. However, a general chapter is only applicable if it is explicitly referenced in a monograph.
In December 2014, DNA barcoding became an official test published in USP-NF general chapter. However, no individual monographs in USP-NF currently make explicit references to this general chapter. As DNA barcoding technology evolves, it is possible that some USP monographs may include it in the future.
It is important to note that some manufacturers may choose to adopt individual tests from USP general chapters in their quality control practices. While this is perfectly acceptable practice, it does not establish compliance with a USP monograph unless: (1) the USP general chapter test is conducted, in part, to meet the requirements of a monograph, and (2) all other tests and specifications required in that monograph are met by the manufacturer.
- Many manufacturers already have their own private standards for quality. Isn’t a public standard redundant?
Public standards, rather than private ones, provide scientists, governments, manufacturers and others a common and transparent measure to judge an article’s quality. Without adherence to a public standard, the uniformity, consistency and quality of ingredients and products is ensured by the manufacturer alone, but cannot be known by others. Therefore, the quality of dietary supplements remains an “unknown” for consumers.
Only in the event of an inspection of a company’s good manufacturing practices (GMPs) can more be known about a manufacturer’s quality specifications. Given the large number of dietary supplement manufacturers and supplement products on the market today, it is challenging for regulators to keep up with inspections that ensure compliance with GMPs due to limited resources. The existence of public quality standards in the marketplace is a key element of the safety net that helps maintain and improve public health, by providing quality measures that are known by all and which everyone can strive to achieve.
- Who in responsible for developing USP’s public standards?
A cadre of experts from industry, academia, regulatory agencies and other stakeholder groups volunteer their knowledge and expertise to USP’s standards-setting process. In addition, USP’s “public” process includes a 90-day comment period for any new or revised standard, and all input—regardless of its source—is taken into consideration by USP’s experts when developing a standard.
Even outside of a formal 90-day comment period, any interested stakeholder has an opportunity to request a revision to a USP standard and provide comments.
To learn more about USP’s process for developing a public monograph, read this blog post in USP’s Quality Matters.
Gabriel Giancaspro, Ph.D., is vice president of foods, dietary supplements and herbal medicines at U.S. Pharmacopeia.