In 2022, three Food and Drug Administration inspectors headed to India to investigate a massive Sun Pharma plant that produces dozens of generic drugs for Americans. Over two weeks, they found dangerous breakdowns in the way critical medications were made, and the FDA ultimately placed the factory on an import ban — prohibiting the company from shipping drugs to the United States.

The agency, however, quietly gave the global manufacturer a special pass to continue sending more than a dozen drugs to Americans even though they were made at the same substandard factory that was officially banned from the U.S. market.

It wasn’t the first time. Here are the key takeaways from ProPublica’s 14-month investigation into the FDA’s oversight of foreign drugmakers:

• Over a dozen years, the agency entrusted to protect America’s drug supply gave similar exemptions to some of the most troubled foreign drugmakers in India, allowing factories banned from the U.S. market to continue shipping medications to an unsuspecting American public.

• A secretive group inside the FDA exempted the medications from import bans, ostensibly to prevent drug shortages. With each pass, the agency dismissed warnings from its own inspectors about dangerous breaches in drug quality on factory floors. All told, the FDA allowed into the United States at least 150 drugs or their ingredients from banned factories found to have mold, foul water, dirty labs or fraudulent testing protocols. Nearly all came from factories in India.

• The FDA did not regularly test the drugs exempted from import bans to see if they were safe or actively monitor reports about potential harm among patients. And as the drugs circulated in the United States, the agency kept the practice largely hidden from the public. The FDA said it put protective measures in place, such as requiring third-party oversight of factories to ensure the exempted drugs were safe.

• Some of the exempted drugs were recalled — just before or just after they were exempted — because of contaminants or other defects that could cause health problems. And a ProPublica analysis identified more than 600 complaints in the FDA’s files about the exempted drugs at three factories alone, each flagging concerns in the months or years after the medications were excluded from import bans. The reports cite about 70 hospitalizations and nine deaths.

• Janet Woodcock, who for more than two decades led the FDA’s Center for Drug Evaluation and Research, said she didn’t see a need to inform the public about the drugs from banned factories because the agency believed they were safe and that such information would create “some kind of frenzy” among consumers who might seek to change their prescriptions. “We had to kind of deal with the hand we were dealt,” she said, noting she supported the exemptions to deal with chronic drug shortages.

• Decisions made by the FDA decades ago gave rise to the use of exemptions. In the 2000s, as the cost of brand-name drugs soared, the FDA approved hundreds of generic drug applications for foreign manufacturers that had been in trouble before, companies well-known to the inspectors working to stamp out safety and quality breakdowns.

• The exempted drugs that have come to the United States include antibiotics, chemotherapy treatment, antidepressants, sedatives and epilepsy medication.

Sun Pharma did not respond to multiple requests for comment. When the FDA imposed the ban, the company said it would “undertake all necessary steps to resolve these issues and to ensure that the regulator is completely satisfied with the company’s remedial action. Sun Pharma remains committed to being … compliant and in supplying high-quality products to its customers and patients globally.”