If you are a Mayo Clinic patient, this could include protected health information. Viagra vs. Viagra is not FDA-approved for use in females, but a healthcare provider may prescribe it off-label. What should I do if I forget a dose? Take sildenafil as needed before sexual activity. We recognize that some people who identify as women do not have the same biological characteristics that are depicted in this article What Happens When a Woman Takes Viagra? Talk with your healthcare provider about your sex life and desired use.These drugs are dubbed “female Viagra,” as a play on the medication for men to alleviate erectile dysfunction. They work in the body in different ways and are also administered differently. In most males,* Viagra works within 1 hour after it’s taken. It’s possible that Viagra can begin working within 30 minutes of being taken. But other times, it may take up to 4 hours to start. US residents can call their local poison control center at Canada residents can call a provincial poison control center. Symptoms of overdose may include severe dizziness.