How long in advance can taking Viagra be effective

Wanaike is generally recommended to be taken 30 minutes to 1 hour before sexual activity, and the specific onset time is affected by individual differences, diet, drug interactions, and other factors. Sildenafil, the main component of Viagra, enhances erectile function by inhibiting phosphodiesterase 5. It is absorbed faster on an empty stomach, and a high-fat diet may delay drug absorption. Middle aged and elderly patients or those with chronic diseases such as hypertension and diabetes may slow down drug metabolism. The combination of nitrate drugs may cause severe hypotension and must be absolutely avoided. Some patients may experience mild adverse reactions such as headaches and facial flushing, which usually resolve on their own. In rare cases, Viagra may need to be taken 4 hours in advance to show efficacy, which is related to pathological conditions such as gastrointestinal disorders and liver dysfunction. A very small number of patients have low drug sensitivity and need to adjust the dosage or change the treatment plan under the guidance of a doctor. If there are serious reactions such as abnormal vision or sustained erection for more than 4 hours after taking medication, medical attention should be sought immediately. Before using Viagra, a cardiovascular risk assessment should be conducted to avoid taking it with grapefruit juice. Maintaining a regular schedule and controlling underlying diseases can help improve the effectiveness of medication. It is recommended to use medication under the guidance of a professional physician, regularly check liver and kidney function, and not increase or decrease the dosage without authorization or use it in combination with other aphrodisiacs.