Frequently Asked Questions about USP Verification Program for Dietary Supplements

What is the verification process?

USP's Verification Program is a multi-step process. It begins with a pre-audit review, which entails an initial assessment of the company's quality system infrastructure. The program is designed to ensure that critical elements of a company's manufacturing systems are in place prior to conducting extensive site audits, documentation review, and product testing. (See Verification Program process graphic)

  • When the Verification Program's staff has determined that a company's manufacturing infrastructure is in place, an extensive on-site audit of the manufacturer's facility and manufacturing operations is conducted. The audit covers all aspects of the manufacturing operation from receiving materials to shipping of the final product. The on-site audit goes a step further than most programs by ensuring that the system controls and operation used to manufacture a product are functioning properly.
  • Upon successful completion of the on-site audit, an extensive review of quality control and manufacturing documentation is performed on specific lots of products. These documents demonstrate that a manufacturer is producing products according to their specifications, as per USP manufacturing practices. The review of these documents is designed to identify areas of improvement for all aspects of the manufacturing process that ensures that a quality product is obtained.
  • Once the manufacturer has met the requirements of the documentation review, the program's staff tests a statistically determined number of the manufacturer's products against specifications and ingredient label claim. This step primarily confirms the observations obtained from the on-site audit and review of product documentation. The program's staff works closely with the manufacturer to resolve any issues that may arise during testing. Other programs merely report test results.
  • If a dietary supplement manufacturer has reached this point in the program, they have met the requirements of the program, and the product under review is awarded the USP verification mark. To ensure that the product continues to meet the requirements of the program, the program staff conducts market surveillance product testing, product documentation review, and manufacturing site audits, on a continual basis.

What does a USP Verification Program GMP review consist of?

USP's Verification Program is designed to be the most rigorous program currently available. It was created to help dietary supplement manufacturers meet USP's manufacturing practices for dietary supplements, and proposed FDA good manufacturing practices (GMPs).
When manufacturers enter the program, they are required to submit extensive documentation about their manufacturing operations. The documentation provided by a manufacturer must demonstrate that they have the quality assurance (QA) systems needed to produce quality dietary supplements. USP evaluates the QA systems, which consist of 15 different program elements that address matters such as employee training, document management, equipment calibration and maintenance, manufacturing and laboratory control procedures, and product shelf life evaluation. An on-site audit of the manufacturing operation is conducted to ensure that the QA systems are functioning properly.

When is the USP verification mark granted to a dietary supplement product?

Upon successfully meeting the requirements of the verification process, the manufacturer's product is awarded the use of the USP verification mark. The manufacturer may display the mark only on specific products that have met all of the requirements of the verification process.

Why does USP utilize its own laboratories to test products?

Unlike pharmaceutical drugs with single active components, dietary supplements may contain several dietary ingredients, or might be botanical products that are extremely complex in chemical composition. Proper knowledge, skill, and experience are essential to ensure that accurate results are obtained. USP scientists have extensive experience in evaluating both drug and dietary supplement products. USP has multiple stages of test data review to provide added assurance that the test results and interpretations are accurate.

Can consumers assume that a USP-verified supplement is safe?

USP's Verification Program addresses the issue of dietary supplement safety in several ways. The program's staff, in consultation with USP's Dietary Supplement Information Expert Committee, evaluate each product's ingredient content. Those products that contain ingredients that the committee finds to have a safety risk will not be accepted into the Verification Program. The Verification Program, however, does not comprehensively address this broad issue. No single program or organization could be expected to completely address the issue of safety. Determining the safety of dietary supplements is a broad undertaking, and includes assessment of drug interactions, contraindications, and side effects. USP's Verification Program does ensure that supplements contain the ingredients stated on the label, in the stated amounts, and that they meet acceptable limits for contaminants such as heavy metals, pesticides, dioxins, furans, PCBs, and microbes. The program ensures that the products are manufactured using safe, sanitary, and well-controlled procedures.

The Verification Program helps protect and inform consumers by providing them assurances that the products with the USP verification mark will not contain harmful levels of contaminants, toxic botanical species, or greater amounts of active/marker compounds than that indicated on the label.

Can consumers assume that a USP-verified supplement is effective?

USP's Verification Program will not accept a dietary supplement into its program if it does not have the proper performance characteristics (e.g. dissolution or disintegration). Products certified by USP will be required to dissolve or disintegrate properly, meeting USP monograph requirements, thereby releasing the nutrients to dissolve and making them available to the body.

USP's Verification Program does not comprehensively address the issue of efficacy of a dietary supplement. The efficacy of dietary supplements can vary between consumers. There is not a single or simple way to completely characterize efficacy of a dietary supplement. Studies of dietary supplement efficacy require governmental, financial, educational, and industrial resources, likely on an international level, to thoroughly address the issue.