Tadacip increases the flow of blood to the penis by relaxing the blood vessels there. Additionally, this medication relaxes the muscles in the bladder and prostate gland, which helps to alleviate the symptoms of an enlarged prostate gland. Tadacip should be taken at least 30 to 60 minutes before engaging in sexual activity if you have erectile dysfunction. Only when you are sexually stimulated can this medication help you get and sustain an erection.