For ten years, the blood testing firm Theranos has made big business from its proprietary system, which the company claims allows patients to have just a finger prick for testing that previously required uncomfortable and cringe-inducing blood draws. But recent investigations by the Wall Street Journal and others have drawn attention to holes in the company’s claims that have led some analysts to question the company’s value.

Theranos is valued at $10 billion, yet some analysts are questioning exactly what the company offers, according to Inc. Theranos was found by Elizabeth Holmes, who dropped out of college at 19 to start the company, and who has no scientific background or medical device engineering experience.

Theranos offers patients testing for about 240 health screenings, and partners with drug stores and doctors across the country for referrals. About 40 Walgreens stores in Arizon and California operated Theranos “wellness centers” where patrons could have blood samples taken from finger pricks for certain tests.

While the company has been in test development mode, Theranos has admitted that it uses competitor’s machines for some of its testing. But the recent Journal article found that the company’s use of common machines was widespread, with the company using its patented “Edison” machines for just 15 of the 240 tests.

The Journal also exposed Theranos’ failures to properly conduct government required proficiency testing to show that its methods are sound. In light of the revelations, Walgreens said it would not be expanding the integration of the company test centers into its 8,200 drugstores nationwide.

Theranos called the Journal story, “Factually and scientifically erroneous, and grounded in baseless assertions by inexperienced and disgruntled former employees and industry incumbents.” But the Food and Drug Administration has requested new data from Theranos on its testing process, and banned the company from using its small vials for collection and transport of blood samples, calling the vials unapproved medical devices.

The FDA has also ordered Theranos to stop using the Edison technology for all but one test, meaning that patients who choose Theranos will still need to have a full blood draw from their arm. This leaves the company with no competitive advantage over other blood testing firms.