FDA is advising pharmaceutical companies to test certain nitrogen-rich drug ingredients for melamine. Although the agency says it “has no reason to believe that the U.S. pharmaceutical supply is contaminated with melamine,” it issued guidance because of previous events involving the industrial chemical in U.S. pet food and Chinese infant formula. In both cases, melamine, which is high in nitrogen, was intentionally added to the products to boost the results of protein analyses. If consumed at high enough levels, melamine can cause kidney failure and death. Of particular concern to FDA are drug ingredients or raw materials that contain more than 2.5% nitrogen and those for which purity or strength is determined on the basis of nitrogen content. FDA has not yet established a safe level of melamine in drugs but cautions that contamination of any type can lead to less effective drugs and potential long-term exposure risks. The agency recommends that pharmaceutical manufacturers use a method to test for melamine that has a detection limit of at least 2.5 ppm to ensure that drug components are not contaminated.