The FDA's investigation was carried out between Aug. 25 and Sept. 16 and raises questions about Theranos' quality control.
"Quality audits have not been performed," the agency said. "Specifically, you have not monitored your Quality Management System through internal quality audits; you had no documented internal quality audit schedule to monitor your Quality Management System until after the start of this inspection."
In a statement, Theranos said: "We believe that we addressed and corrected all the observations at the time of, or within a week of, the inspection and have submitted documents to FDA that say so, including extensive documentation."
The FDA's investigation reports were posted less than two weeks after The Wall Street Journal reported that the company — which is valued at $9 billion — had exaggerated the success of lab tests used on its own machines.