Millions of men credit Viagra for saving their sex lives. But nearly two decades after hitting the market, Viagra is now being credited for literally saving the lives of children.

Doctors say Victoria Dooley will live to see her fourth birthday thanks in part to Viagra.

“It’s been working wonders,” said Victoria’s dad, Shawn.

Victoria was born with a rare condition causing one side of her heart to fail.

“You can see it (was) pretty enlarged and not functioning normally,” said Dr. Anne Chun, an assistant professor of pediatrics and NYU Langone Medical Center.

Victoria has had three surgeries so far, and Chun says she will likely need a heart transplant when she’s a teen.

“Over time, her function will continue to decrease,” Dr. Chun said.

But by taking a low dose of Viagra now, Victoria is able to function at a greater capacity, as well as increase her life expectancy.

“It really helps to relax the blood vessels so that blood will flow normally from the body into the lungs and allow for normal oxygen levels,” Dr. Chun explained.

More than 20 years ago, Viagra was first tested to lower blood pressure, when it was realized that it could raise something else.

And while it’s still prescribed to adults with certain heart problems, when giving to children, it’s considered “off label use”.

Still, several children’s hospitals across the country are reporting similar life-saving results in kids with serious lung and cardiac problems.

“When you first hear about it,” Shawn Dooley said, “you think about it more for the adult uses.”

While this treatment was a little surprising, Victoria’s parents are grateful for how it’s allowing their daughter to live the life of any other four year old.

“She’s in swimming now, going to dance, in pre-school,” her dad said.

Small doses of Viagra are also given to premature babies to help them overcome a potentially lethal lung problem called pulmonary hypertension, which makes it hard for the hard to pump blood through the lungs and is the leading cause of death in preemies after their first month of life.