Cenforce 120 mg works effectively when the patient is sexually stimulated. Once a man takes Sildenafil Citrate Cenforce 25 or Cenforce 100 and has sex, his erection will go away after intercourse, just like it would normally. For this pill to work as expected, it should be taken 15 to 30 minutes before the planned sexual intercourse, and consuming fatty foods should be avoided so that it activates faster.