”Viagra, whose scientific name is phosphodiesterase type 5 inhibitor (PDE-5 inhibitor), is the most commonly used first-line drug in the international treatment of erectile dysfunction. Viagra, the first PDE-5 inhibitor marketed by Pfizer, is called “Viagra” because of its ability to enhance male erectile function and its phonetic translation. There are also two other PDE-5 inhibitors available: Cialis and Elidel. Many people in the society lack a clear understanding of Viagra and wrongly believe that taking Viagra will cause addiction, or contain hormones that are harmful to the body, or that it is a cure for the symptoms but not the root cause. In fact, it is not. PDE-5 inhibitors are new drugs that target the physiological mechanism of penile erection to treat erectile dysfunction. Under sexual stimulation, through a series of neuroendocrine factors, it induces the release of nitric oxide (NO), a key transmitter involved in penile erection, from nerve endings and vascular endothelium, which leads to an increase in the level of cGMP, the second messenger, thus the smooth muscle of penile corpus cavernosum relaxes, the blood sinus is filled with blood, the veins are pressed closed by the white membrane of corpus cavernosum, and the penis The penis becomes progressively harder. Many studies have confirmed that the NO-cGMP pathway is an important pathway involved in penile erection. PDE-5 inhibitors are designed to increase the level of cGMP by inhibiting the activity of PED-5, thereby improving erectile function. PDE-5 inhibitors are designed to inhibit the degradation of cGMP in the presence of sexual stimulation to aid in erection, making the erection harder and prolonging erection maintenance. The awake state does not produce spontaneous erections in the absence of sexual stimulation. However, since PDE-5 inhibitors are gradually metabolized in the body, their effect is temporary and can only be maintained for a period of time, and lose their effect after the drug is completely metabolized. On the contrary, animal tests and clinical studies have confirmed that long-term use of PDE-5 inhibitors can improve erectile function: the erectile function of the patient will be improved after long-term use, and the resulting anxiety and depression will also be improved accordingly, eliminating the negative influence of psychological factors on erection; the long-term engorgement of the cavernous body also It can improve the blood supply and oxygen supply to the smooth muscle cells of the cavernous body, inhibit the atrophy of smooth muscle cells, maintain the ratio of muscle to fiber in the cavernous body, and inhibit cavernous fibrosis. Clinical studies have confirmed that after long-term use and discontinuation of the drug, the vast majority of patients can maintain a better level of erectile function in the long term. Therefore, taking Viagra does not produce addiction, but is beneficial to erectile function. For patients with less severe ED, there is also a healing function. Therefore, Viagra can be used to treat both the symptoms and the root cause. Clinical studies have confirmed that the efficiency of PDE-5 inhibitors on erectile dysfunction treatment can reach about 70%, especially for psychological erectile dysfunction is more obvious, for some difficult to treat ED patients such as diabetic ED, cardiovascular ED, etc. also have considerable effect. Of course, PDE-5 inhibitors are different from the wide variety of so-called sexual health products sold in social health stores, this is a therapeutic drug, there are some matters that must be noted when taking it, otherwise it will affect the effectiveness of the drug, so it is recommended that patients should go to the hospital for the first time to consult.