Wherein the drug sildenafil is an agent for treating erectile dysfunction in men   Since 1998, sildenafil has been known under the name Viagra on the market in order to help men with erectile dysfunction. Erection problems in the past were an absolute taboo subject, so this Potency has certainly helped to put this but very intimate issue in the public eye. Men no longer need to buy under the cloak of secrecy, their power resources, for there is now much more understanding in this field. Viagra by a new awareness was on this topic and it has been seen that erectile dysfunction does not only affect old men, but about 2% of men under 40 years old are aware of this problem and wish to become an unsatisfactory sex life, of course, not resign.   Sildenafil ensures a dilation of blood vessels in the penis of the man. This allows more blood flow into the penis and it comes to a steadfast, firm erection. Onset of action occurs after 15-30 minutes and is like a very healthy person, caused by an increased sex drive.   Erection ends reaching orgasm and it is possible within the duration of effect of 4-5 hours, to obtain a re-erection. After taking sildenafil can cause few side effects. The most common adverse events included headache, a striking facial redness. In very rare cases it can cause dizziness, palpitations, nasal congestion and impairment of vision.