The FDA has released documents related to its visit to Theranos' labs, and they don't look good.

Theranos, a $10 billion company that says its blood tests can be done accurately with a single drop of blood, has come under fire after a lengthy Wall Street Journal exposé questioned just how revolutionary the startup was.

The reports are Form 483s, which are issued at the end of inspections when investigators see anything that may violate the Food Drug and Cosmetics Act. They are from an FDA visit that took place between August 25 and September 16, and they are heavily redacted. Nevertheless, they are worrisome.

Take a look:

Notably, the forms relay observations about Theranos' proprietary technology that collects tiny samples of blood.

The FDA claims the containers Theranos has been using to collect blood, known as nanotainers, never got regulatory approval: "You are currently shipping this uncleared medical device in interstate commerce, between California, Arizona, and Pennsylvania."

Here are some of the other main observations sent to Theranos CEO Elizabeth Holmes and president/COO Ramesh "Sunny" Balwani.

Observation 1: "Design validation did not ensure the device conforms to defined user needs and intended uses."

Essentially, the FDA investigators concluded that at the time of their research, the proof the device was doing what it was supposed to wasn't strong enough.

Observation 2: "The design was not validated under actual or simulated use conditions."

Here the FDA is elaborating on its first observation. The technology in Theranos' labs, the FDA noted, wasn't numbered and listed the way it should be under FDA regulations.

Observation 3: "Design input requirements were not adequately documented."

Here, the FDA digs into Theranos' use of TSCDs, or Terumo sterile tubing welders, used in the lab as part of blood testing.

Observation 4: "Results of the design risk analysis were not adequately documented."

Documentation seemed to be a key sticking point for the FDA inspectors.

Observation 5: "Documents were not reviewed and not approved by designated individual(s) prior to issuance."

It appears as if this isn't the first time Theranos has butted heads with FDA inspectors: "This document was provided as a follow-up to the failures in your design validation conducted in 2014," the FDA report says.