How does Viagra treat ED?  Viagra and comparative ED drugs like Cialis (tadalafil) and Levitra (vardenafil) work by loosening up muscles and supply routes inside the penis, which assists more with blooding arrive at the penis. At the point when stirred—and just when stimulated—the mix of unwinding and expanded blood stream helps fill the penis with blood. That is the means by which you're ready to accomplish an erection.  How rapidly accomplishes Viagra work?  Subsequent to taking Viagra, the drug rapidly…