These days, we know where almost everything comes from. Everyday items like food, clothes and pens all carry labels listing where things are grown, manufactured or even designed.

So why is it so hard to find where prescription drugs are made?

That question set off a 14-month investigation into where our medications are made, how the FDA polices drug manufacturers and what happens when inspectors report issues inside factories.

The vast majority of prescriptions filled in the United States are for generic drugs, which are often far cheaper than brand-name alternatives.

For years, Congress, doctors and watchdog groups have questioned the quality of generic drugs made overseas. India produces about half of all generics used in the U.S., but the labels on pill bottles often don’t list where a drug is manufactured. Inspection reports describe unsafe manufacturing conditions at generic drug factories, but the Food and Drug Administration redacts the names of the medications made in those factories. That means if drugs made in errant factories wind up in your medicine cabinet, you’d have no way of knowing.