Vidalista Black 80 contains tadalafil, which is known for its long-lasting effects. Typically, tadalafil can remain effective for up to 36 hours, which is one of the reasons it's often referred to as the "weekend pill." This extended duration allows for more flexibility in timing sexual activity. However, the exact duration of effectiveness can vary depending on individual factors such as metabolism, health conditions, and other medications being taken. If you have specific concerns or experience unexpected effects, it’s best to consult with your healthcare provider.