Viagra is now usually the first drug for erectile dysfunction. So if you have any problems with potency, you can take Viagra and treat begins. It is to be noted, that 90% of men who have erectile dysfunction prefer to buy as the first potency drug Viagra. It should also be noted if they suffer from erectile dysfunction, so the doctor recommends Viagra first. So, what are the benefits of Viagra? Viagra the most researched and the most safe medicine. It mean, that you can be sure that this preparation is not dangerous for you. More good news: thanks to its optimal composition it has almost no side effects. But like all medicines Viagra also has several drawbacks. It is not recommended to take this drug with other drugs, in particular, with drugs that have nitrates in its composition. You also might notice that the tablets are not ordinary form and some patients claim that it is not very pleasant to swallow them. For those men who have no other health problems, Viagra is absolutely safe. During an emotional arousal Viagra Sildenafil helps men achieve a healthy, sustainable erection. The effect of the drug Viagra is based on the normalization of the blood flow into the erectile tissue of the penis: after taking Viagra arteries that supply the penis with blood, expand, where to fill the erectile tissue of the penis with blood, hence they make elastic, causing lasting natural erection. The medicine should be taken about 1 hour before sexual intimacy with a little water. Viagra starts within 30-40 minutes after taking an effect. However, abundant or slow down the action of fatty meals something. The standard dose for most men is 50 mg (half a tablet). The dose may be increased or decreased depending on the strength of the effect and tolerability. The maximum daily dose is 100 mg. The minimum dose of 25 mg is recommended for elderly men and patients with kidney or liver disease.