Fildena can help with erections for several hours, depending on the strength and your body's response. Fildena commonly contains sildenafil citrate, the same active ingredient as Viagra. How long does Fildena last? Starts working: Usually within 30–60 minutes. Peak effect: Typically around Fildena after taking it. Duration: Usually around 4 hours, although the effect can sometimes last longer. Sexual stimulation: Required for it to help you get an erection. A heavy, high-fat meal may delay how quickly it starts working. Does a higher dose last longer? Not necessarily. Higher doses can increase side effects without significantly extending the duration. Sildenafil doses above 100 mg in 24 hours are not recommended for erectile dysfunction. Never combine Fildena with Viagra, Malegra, Silditop, or other erectile dysfunction medicines. Avoid it entirely with nitrate medicines used for chest pain.