The US Food and Drug Administration recommends using “Liquid Chromatography-Hight Resolution Mass Spectrometry Method” for testing ranitidine rather than the method apparently used by online pharmacy Valisure that led them to ask the agency to halt production and order recalls. HBW looks at the difference between high- and low-temperature testing methods, the timeline of the testing in question and the subsequent notifications, the request by the FDA for manufacturers to conduct their own laboratory testing to assess levels of NDMA, and the actions by key pharma companies using ranitidine in their products including which companies are stopping production and conducting recalls in which regions.