Although the data gathered form the clinical trials looked spectacular, many health professionals still advise patients to take a cautious approach when considering using Viagra.  Viagra does not help to increase the desire for sex, and it does not directly lead to an erection.  It simply affects the response to stimulation to the penis.

The following are recommendations by the FDA that users should follow before taking Viagra as a treatment for ED:

1. If you are taking nitrates, Viagra may not be a good choice as the mixture of the two can cause lower blood pressure.
2. Viagra should not be used by women or children.
3. It is good to have an examination to help determine the cause of erectile dysfunction.
4. If you suffer from a medical condition like sickle-cell, leukemia, or have an unusually shape to your penis it is advised that you do not take Viagra.
5. Be sure to let your physician know what medications you are taking (including over the counter) as certain medications will interact with Viagra.
6. If you are taking other ED treatments it is recommended that you do not take Viagra as there have been no studies to show how they will react with one another.