Tadalafil and Sildenafil are both commonly used drugs for the treatment of erectile dysfunction, each with its own characteristics, and there is no one drug with obvious superiority, it depends on the needs of the patient when using them. Tadalafil is a long-acting drug, and sildenafil is a short-acting drug, and their characteristics are different. Firstly, the duration of action is different. Tadalafil is effective within 36 hours after taking, and the best effective time is within 28 hours; sildenafil can maintain its effect for 8 hours after taking, and the best effect is within 4 hours. Secondly, the time of onset of action is different. Tadalafil needs about 2 hours to take effect, so it needs to be taken about 2 hours in advance; sildenafil only needs to be taken about one hour in advance. Thirdly, another factor that affects the choice of drugs for patients is the price, the price of tadalafil is significantly higher than that of sildenafil. If a patient has the requirement of continuous life within the last few days, you can choose tadalafil, so that you can avoid repeated doses. If there is a need for sexual intercourse on the same day, it is more appropriate to choose sildenafil directly.