From 2013 to January 2017, Mattis was a board member of Theranos, a health technology company that claimed to have devised revolutionary blood tests using very small amounts of blood. Previously, in mid-2012, a Department of Defense official evaluating Theranos's blood-testing technology for the military initiated a formal inquiry with the Food and Drug Administration about the company's intent to distribute its tests without FDA clearance. In August 2012, Theranos CEO Elizabeth Holmes asked Mattis, who had expressed interest in testing Theranos's technology in combat areas, to help. Within hours, Mattis forwarded his email exchange with Holmes to military officials, asking "how do we overcome this new obstacle". In July 2013 the Department of Defense gave Mattis permission to join Theranos's board provided he did not represent Theranos with regard to the blood-testing device and its potential acquisition by the Departments of the Navy or Defense.