Viagra is a drug used for male sexual dysfunction, which is often referred to as impotence and premature ejaculation in sexual life. Both conditions are available, and the repercussions of using it are relatively good. It can effectively help impotence patients with penile filling and erection, and premature ejaculation patients to effectively achieve prolonged ejaculation, thus achieving a coordinated and stable sexual life. Although Viagra has a good effect on impotence and premature ejaculation, it still cannot be used for a long time because this drug has side effects. Long-term use may result in abnormal erections, such as persistent erections, and if the erection lasts for more than 4 hours, you need to seek medical attention in time, otherwise there is a risk of permanent damage to the penis. It may also cause dizziness, stomach pain, loss of vision and hearing. So it is recommended that it is best not to use it, you can take Chinese herbal medicine to regulate the kidney, or go to a regular hospital for treatment.