Cenforce D is a popular medication used to treat erectile dysfunction (ED). It contains sildenafil as its active ingredient and is produced in strengths of 25mg, 50mg, 100mg and 150mg. It helps men achieve a good erection when sexually stimulated. Side effects may include headaches, flushing, indigestion and a stuffy nose. Cenforce D is a brand of generic sildenafil citrate that is used to treat erectile dysfunction (ED). It is a popular medication due to its effectiveness and availability in a range of dosage forms, including tablets and oral jelly. Cenforce is available without a prescription and can be taken an hour before sexual activity. It works by increasing nitric oxide in order to relax the smooth muscles in the penis. This helps to increase blood flow to the penis and produce an erection.