Viagra is the common name for Sildenafil Citrate Tablets, 3 types of effects may occur after taking this drug: satisfactory effect, poor effect, and no effect, depending on the individual. Sildenafil citrate tablets are suitable for the treatment of erectile dysfunction in men over 18 years of age, this drug is prohibited for those who are allergic to it, and also prohibited with guanylate cyclase agonists (such as levocetirizine), nitrate drugs (such as nitroglycerin) and other medications, the use of drugs in the process of the possibility of headache, nausea and other adverse reactions. 1. Satisfactory efficacy: that is, the symptoms of erectile dysfunction have been significantly improved, and the penis can achieve and maintain sufficient erection to complete a satisfactory sex life. Mostly seen in line with the indications, standardized and reasonable use of drugs. At this time should follow the doctor’s advice to continue to take the drug according to the course of treatment, in order to strive for a good prognosis. 2. poor efficacy of the situation: that is, although the symptoms have been relieved, but the penile erection can not fully meet the needs of sexual life. Mostly seen in the more serious condition, insufficient dose of drugs, the body of the poor sensitivity to the drug. This time should be under the guidance of the doctor to adjust the dose to continue to use the drug observation or change the type of drug. 3. no efficacy of the situation: that is, the symptoms of erectile dysfunction have not been improved at all. Mostly seen in the non-compliance with the indications, not in accordance with the provisions of the drug, the body of the drug-resistant or very serious condition, can also be seen in the use of the drug did not receive sexual stimulation. The first few cases need to adjust the treatment program under the guidance of the doctor, and the latter case should be given sexual stimulation before observing the effect. To sum up, those who have the need to use sildenafil citrate tablets must standardize the use of medication under the guidance of a doctor, do not blindly take medication, so as not to cause adverse consequences.