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Dietary Supplements: Structure/Function Claims Fail To Meet Federal Requirements


The Government Accountability Office and public interest groups have raised concerns about a specific type of claim-called a structure/function claim-that manufacturers may use on dietary supplement labels. Manufacturers have used these claims to promote health benefits of their products. Stakeholders have urged FDA to strengthen oversight of these claims because they are potentially misleading and may lack scientific support. FDA lacks authority to review or approve these claims before products enter the market. Manufacturers must have competent and reliable scientific evidence to show that claims are truthful and not misleading, but they do not have to submit the substantiation to FDA, and FDA has only voluntary standards for it. A manufacturer must notify FDA when it uses structure/function claims, and a product label must include a disclaimer stating that FDA has not reviewed the claim and that the product is not intended to diagnose, treat, cure, or prevent any disease.


We analyzed structure/function claims for a purposive sample of 127 dietary supplements marketed for weight loss or immune system support. We reviewed the claims to determine the extent to which they complied with FDA regulations. We reviewed substantiation provided by manufacturers to describe the quantity and nature of the evidence. We also assessed the accuracy and completeness of notification letters that manufacturers must submit to FDA for their structure/function claims.


Overall, substantiation documents for the sampled supplements were inconsistent with FDA guidance on competent and reliable scientific evidence. FDA could not readily determine whether manufacturers had submitted the required notification for their claims. Seven percent of the supplements lacked the required disclaimer, and 20 percent included prohibited disease claims on their labels. These results raise questions about the extent to which structure/function claims are truthful and not misleading.


We recommend that FDA seek explicit statutory authority to review substantiation for structure/function claims to determine whether they are truthful and not misleading. We recommend that FDA improve the notification system for these claims to make it more organized, complete, and accurate. We also recommend that FDA expand market surveillance to enforce the use of disclaimers for structure/function claims and to detect disease claims. In its comments on the draft report, FDA did not explicitly concur with our first recommendation, but said it would consider it. FDA concurred with our second and third recommendations.