In November Palatin unveiled results of tests on 271 older, impotent men: The drug was 75% effective and produced no more side effects than Viagra.

FORBES: A novel way, perhaps, to treat sexual dysfunction.

Sixty percent of men were rendered impotent by the operation, according to one study.

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In this week's New England Journal of Medicine, an editorial points out that "the strength and maintenance of erections" of men on Viagra were not as good as men who were not impotent.

CNN: Study: Viagra doesn't work for every impotent man

The men were asked in a questionnaire whether they suffered from ED and at what degree they were impotent (mild, mild-to-moderate, moderate or severe).

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