Sildenafil tablets can last for about half an hour to an hour after taking them, the details are related to the patient’s ability to absorb the drug. Sildenafil tablets belong to the phosphodiesterase inhibitor, can be used to improve male erectile dysfunction, can last about half an hour after using the drug, some people’s ability to absorb the drug is relatively strong, may also last for about an hour, the specific circumstances vary from person to person. Drug contraindications: allergic to the product is prohibited; patients taking any dose of nitrate is prohibited; patients who have had a shock, myocardial infarction in the last 6 months is prohibited; patients with pigmented retinitis is prohibited. Adverse reactions: common dizziness, headache, flushing, visual abnormalities, etc.; rare facial edema, muscle aches, panic, hypotension, etc.; rare sudden loss of vision, loss of hearing and diminution. Sildenafil tablets should be used under the guidance of a physician or pharmacist, to avoid private abuse of drugs, so as not to cause adverse health effects.