One of the scientists behind two of the most successful drugs for erectile dysfunction is now working on a cannabis-based “sexual enhancement” for women. Dr. Harin Padma-Nathan is a urologist and sexual-disorders specialist who worked with a team of researchers to develop Viagra and Cialis. While Padma-Nathan is happy to have helped men suffering from erectile dysfunction for over 20 years now, Padma-Nathan says sexual dysfunction treatments for women continue to lag behind.