In adults if they use viagra once or twice in week deos it has any side effect in future?

Answer 1

no more side effects than it has any other time. viagra has been approved to be used once a day.

Answer 2

Don't you read the warning labels on prescription drugs? Use of viagra or either of the other two popular brands more than once per week for three consecutive weeks coagulates the blood in the penis and the erection will stay indefinitely. The member then has to be lanced to free the blood to lower the boom. Once the pole has been lowered it cannot again be raised. At that point the only treatment available to a man is a sex change operation. I'd stick with the natural method of foreplay to raise the flag.