Viagra and similar ED drugs work by relaxing muscles and arteries inside the penis, which helps more blood reach the penis. When aroused—and only when aroused—the combination of relaxation and increased blood flow helps fill the penis with blood. That’s how you’re able to achieve an erection. In most cases, Viagra works well and has changed people’s lives for the better.
Viagra can help men who cannot achieve or sustain an erection due to erectile dysfunction. It improves the erectile response when a man is already sexually stimulated, but it does not provide sexual stimulation. If there is no sexual stimulation, viagra will not work.