Viagra generally refers to sildenafil citrate and does not provide time-delaying and long-lasting effects. Sildenafil citrate is used clinically for erectile dysfunction; according to the drug’s specification, this drug does not have time-delaying and long-lasting effects. Patients with a short sex life who are diagnosed with premature ejaculation should be treated with a 5-hydroxytryptamine reuptake inhibitor, such as dapoxetine hydrochloride, as prescribed by their doctor. If it is not premature ejaculation, there is no need to overdo sexual time. Sildenafil citrate may cause adverse reactions such as nausea, vomiting, abdominal pain, dizziness, headache, and visual abnormalities in some patients after administration. This drug is contraindicated in people who are allergic to this drug; it should be contraindicated during the application of guanylate cyclase agonists and nitrate drugs; and it should be contraindicated in people who suffer from serious cardiovascular and cerebrovascular diseases, pigmented retinitis and other diseases. When used for erectile dysfunction, the cause of the disease should be diagnosed first; abnormal erection (erection for more than 4 hours) should be treated by a doctor. How to apply this drug, must follow the doctor’s instructions; for premature ejaculation and other diseases of patients, should consult a doctor for timely examination, to be targeted treatment, do not arbitrarily apply.