Tadasoft 20 mg is an FDA-approved drug for the treatment of erectile dysfunction in men. It is the only drug proven to treat erectile dysfunction for up to 36 hours. Tadasoft inhibits with the making of a hormone called PDE5.It relaxes the blood vessels that surround the penis to allow for increased blood flow during sexual arousal. With Tadasoft, men can easily get and maintain a hard erection after sexual stimulation. You will get an erection only after sexual arousal and the erection will go away on its own.