To know if Cenforce 100 is working, observe how your body responds within 30 to 60 minutes after taking it. Signs it’s effective include achieving and maintaining a firm erection during sexual stimulation. Physical arousal is still necessary for the medication to work. If you notice improved performance and confidence without severe side effects, it's likely effective. However, if there’s no change after a few attempts or side effects persist, consult your doctor to adjust the dose or explore alternatives.