The pharmaceutical company knew about the danger, but concealed it. In nearly half a century, Zantac has become the world's best-selling prescription drug. In 2019, scientists determined that it wasn't the drug's main component(Ranitidin) that was toxic, but the substance it created, N-Nitrosodimethylamine (NDMA). As of 2020, countries began banning the sale of the drug and revoked the license.
Since the 1970s, NDMA was considered one of the most powerful carcinogens. The substance provoked cancer in every species of rat tested. A single dose of less than a milligram can cause cell mutation and tumor development, while 2 grams can kill a person in a few days.
It is possible that Glaxo knew about the problem from the beginning, but did not indicate this in the results of the drug's carcinogenicity study. In addition, the company rigged the drug trials to get the right conclusions.