Viagra is the trade name, generic name is sildenafil citrate tablets, in general, a single recommended dose is 50 mg, but due to the existence of individual differences, the dose can be increased accordingly, but the maximum should not exceed 100 mg. The main ingredient of Sildenafil Citrate Tablets is Sildenafil Citrate, which is an erectile dysfunction medication, and is clinically used for the treatment of erectile dysfunction in men. For most patients, the routinely recommended initial dose is 50 mg for adults and 25 mg for seniors >65 years of age, taken on demand approximately 1 hour before sexual activity; however, it can be taken any time within 0.5 to 4 hours before sexual activity. Based on efficacy and tolerability, the dose may be increased to 100mg (maximum recommended dose) or decreased to 25mg. The drug should be taken up to once daily. The recommended dose of sildenafil does not work in the absence of sexual stimulation. Adverse reactions such as ataxia, headache, palpitations (rapid heartbeat, often accompanied by panic) may occur after taking the drug. Sildenafil is prohibited in combination with nitrates, the drug is contraindicated in women, people who are allergic to the product, children, people whose recent cardiovascular state does not allow them to have sex. In summary, the use of drugs should be carried out under the guidance of a professional doctor, do not blindly use drugs on your own to avoid adverse consequences.