It is meant to be taken by men who suffer impotence or erectile dysfunction. As of right now, there is no evidence that viagra can help women with dysfunctions, but studies are currently being conducted. Until the results of these tests are publicized, it is not recommended for any women to take this pill. Some cases where viagra had failed were due to emotional or other underlying causes. If viagra does not work, there are other alternatives to consider, such as penile injection therapy, but men should check with their physicians before making any decisions.
Side effects can include headaches, nausea, and diarrhea.
There is no effect on sperm count or motility. Viagra should not be taken at all by men taking nitrates. This could lower the blood pressure to unsafe levels. Like any drug, consult a physician to see what treatment is right for you.