In a pilot study of 10 women infected with HPV, three appear to have cleared the virus after taking the supplement daily for three months and remained clear of the virus one month after their last dose of AHCC, a shiitake mushroom extract, says pharmacologist Judith Smith of the University of Texas Health Science Center at Houston. It can be hard to know whether HPV has been vanquished, so the researchers are scanning the women for immune proteins produced in response to the virus. Editor’s Note: This article was updated November 5, 2014 to clarify how long the three women who cleared the virus had taken the supplement.