Thank you for your question. I'm not entirely sure I understand what information you're looking for, but I'll try to explain what I can. Viagra does not have a direct effect on the prostate. Viagra works by relaxing the veins in the penis so that the blood flowing into the penis doesn't flow out. This leads to an erection. There are no known side effects that would affect the prostate. The most common side effects of Viagra are headache, flushing, and diarrhea. You can read more about Viagra and it's side effects here. I hope this helps.
Best of luck,