FDA should ask Congress for more authority to oversee dietary supplements, concludes a Government Accountability Office report. In particular, GAO found that FDA has a limited ability to identify concerns related to the safety of dietary supplements because the agency lacks information on how many companies manufacture them and where those companies are located, the types of products currently on the market, and moderate or mild adverse events reported to industry. Manufacturers of dietary supplements are required to report only serious adverse events such as death, hospitalization, or birth defects. When FDA does identify a safety concern, GAO found that FDA is hindered from removing the product from the market because it does not have mandatory recall authority. In addition, GAO found that FDA devotes insufficient resources to oversight of dietary supplements, such as providing guidance to industry on new dietary ingredients and clarifying the boundary between dietary supplements and conventional foods that contain added dietary ingredients.