As per the research done by National Institutes of Health (NIH), an increasing number of men are reporting problems with erectile dysfunction, or the recurrent inability to get or maintain an erection. Patients with ED report great success with Viagra, Levitra, and Cialis. All three drugs have been approved for the treatment of ED by the Food and Drug Administration, and are available through a regular or an online pharmacy.

The NIH cites a wide range of conditions that account for almost three-quarters of reported cases of ED. Diabetes, kidney disease; chronic alcoholism, multiple sclerosis, atherosclerosis, vascular disease, and neurologic disease are common causes of ED.

Viagra works at treating erectile dysfunction in the first place, by blocking two specific enzymes in the body, known as PDE5 and PDE6, which exist throughout the body, but in higher concentrations in the penis. The problem here: PDE6 also plays an important role in the processes that make vision possible. Thus, blocking the enzyme causes complications with the vision of some Viagra users.

Like Viagra, an estimated number of eighty percent of the people who have tried Cialis have had the opportunity and chance in the mean time to have an erection as well as sexual acts but in comparison with Viagra, the effects and potential of the user lasted for more than thirty six hours after taking the pill; in this period of time the effects were almost constant. A possible explanation for this is the fact that Cialis persists longer in the body than Viagra does. The period of time for blood levels to fall fifty percent for Viagra records four hours, while Cialis makes it up to seventeen hours. This can signify that a twenty five percent of the original doze of Cialis is still in the body at that time.

Levitra, like Viagra, increases blood flow to the penis during arousal. As with Viagra and Cialis, Levitra should not be used more than once a day, and is contraindicated for men who are taking nitrates or alpha-blockers.

Due to the cost of Viagra, Cialis, and Levitra, men are increasingly turning to an online pharmacy to fill their discount prescription. Levitra works by inhibiting the PDE-5 enzymes, which regulate the blood flow into the penis. Due to this reason, it is also referred to as PDE-5 inhibitor. Levitra primarily relaxes the smooth muscles of the penis and enhances the blood flow into the penis. This as a result sources an erection. They buy Viagra over the Internet at an online pharmacy, as well as Cialis and Levitra. Together, the three drugs have provided relief to millions of men and their partners.