Fildena CT 50 should be taken approximately 30 minutes to 1 hour before sexual activity. The effects of Fildena CT 50 can last for about 4 to 6 hours, allowing for a window of time for sexual activity. Fildena CT 50 is available in a 50 mg dosage strength. The appropriate dosage depends on individual factors such as the severity of ED, response to the medication, and other health considerations. It's important to follow the dosage instructions provided by a healthcare provider.