Swallow tablets whole with a drink of water or juice (but not grapefruit juice). For erectile dysfunction, it's best to take sildenafil on an empty stomach. It may take longer to work if you take it with food. Take Cenforce 100mg Tablet about 1 hour before you plan to have sex. Swallow the tablet whole with a glass of water. Inform your doctor if you feel the effect of Cenforce 100mg Tablet is too strong or too weak.