The generic name of Viagra is Sildenafil, the lack of effect of taking Sildenafil may be due to the incorrect method of taking the drug or the lack of adequate sexual stimulation after taking the drug, and if there is alcohol consumption or excessive diet when taking the drug will also have an impact on the use of the drug, it is recommended to take the drug in accordance with the doctor’s instructions. When patients take sildenafil, whether the method of taking it is correct, whether there is sufficient sexual stimulation after taking the drug, as well as taking the drug, whether at the same time there is drinking alcohol, excessive diet, etc., will affect the effect of taking the drug. It may also be caused by taking the medication too early, after the time of its effect. If the patient takes the medication without the effect of sexual stimulation, it also does not work. As the effect time of taking the drug is about 4 hours, it is recommended that it is better to take the product about an hour before intercourse. Taking sildenafil has no effect, it is recommended to consult the relevant professional doctors, and at the same time to maintain a comfortable mood, pay attention to the first time to take the drug to the full amount, full effect, which is also more important.