This is pretty frigging awesome.

Japanese researchers have harvested stem cells from human menstrual blood. These stem cells could potentially be a source of specialized heart cells, which might be used to treat failing or damaged hearts.

...At the meeting of the American College of Cardiology here, Dr. Shunichiro Miyoshi reported that he and his colleagues at Keio University School of Medicine, Tokyo, collected menstrual blood from six women and harvested stem cells that originated in the lining of the uterus, the endometrium.

They were able to obtain about thirty times more stem cells from menstrual blood than from bone marrow, Miyoshi told Reuters Health.

Via Feministe and The Countess. Yes, ladies. Science is cool.