The medicament dilates the blood vessels of the penis during sexual arousal. As a result, blood flow to the penis is increased, leading to a normal erection.

Like many other inventions, the effect of the drug was discovered by accident: in 1992 in clinical trials on volunteers a new drug to treat heart disease.

The drug is not given the expected results, but scientists turned their attention to the "side effect" - increased potency in men. Since 1998, Viagra was first appeared in pharmacies in the US.

We recommend that you be careful with Viagra as this drug appeared on the market relatively recently and therefore insufficiently studied. There have been no reliable large-scale studies that have been published in the press (mostly laudatory articles or published by the manufacturer, or extreme views, denying the usefulness of administration of the drug, competing companies). Do not take Viagra just out of curiosity and to enhance sexual sensations. Remember that everything must be measure and "golden mean" if constantly spurred organism or its separate functions, it will sooner or later be exhausted and there would be problems. And last. Nobody has rejected a healthy lifestyle: Learn harmony with nature, enjoy every day and then you will not need the blue pill.

If taking regularly or intermittently nitrates to treat angina pectoris (e.g. nitrosorbit, kardiket, izoket etc.), and nitrogen donor oxide. In these cases, use of Viagra is contraindicated because it enhances the effect of nitrates and blood pressure can drop to critical limits. If you do not know whether drugs that drink belong to the nitrate - ask your doctor to avoid future problems. Caution should be used in the presence of Viagra anatomical deformity of the penis, diseases accompanied by bleeding, where exacerbation of an ulcer of the stomach and duodenum in the first 6 months after myocardial infarction, stroke, in severe arrhythmia. If blood pressure is above 170/100 or lower than 90/50 refrain from taking Viagra.