Vidalista 2.5mg, which contains tadalafil, typically stays effective for up to 36 hours after taking it. This long duration allows men to achieve and maintain an erection when sexually stimulated during this time. It is important to note that while the medication remains active in the body for this extended period, it does not cause an erection on its own; sexual arousal is necessary for it to work. For optimal results, it is recommended to take Vidalista 2.5mg about one hour before planned sexual activity. The onset of action can vary from person to person, but it usually starts working within 30 to 60 minutes. This flexibility in timing makes it easier for men to engage in spontaneous sexual activity without the need for precise planning.