It enhances the effects of nitric oxide, a natural chemical the body produces during sexual arousal. It relaxes the muscles in the blood vessels of the penis, allowing increased blood flow, which leads to an erection.

Take this medication about 30 minutes to an hour before sexual activity. It can be effective for up to four hours. Swallow the tablet whole with water, and do not take more than one dose in a 24-hour period.

Typically this medication is available in 25 mg, 50 mg, and 100 mg tablets. Your healthcare provider will determine the appropriate dosage based on your needs and medical condition.

While this medication can be taken with or without food, high-fat meals can delay its effectiveness. Alcohol can reduce its effectiveness and increase the risk of side effects, so it's best to limit alcohol consumption when using sildenafil.

Common side effects include headaches, flushing, upset stomach, nasal congestion, and dizziness. These side effects are usually mild and temporary.

This medicine is effective for many men with erectile dysfunction. However, its effectiveness can vary based on individual health conditions and other factors.