A pill that’s proven to increase the lifespan of mice is now being tested on dogs – and could eventually help humans live longer, healthier lives.

What Is Rapamycin?

Rapamycin, a drug that’s been researched over the last decade, has been shown to help mice live up to 60% longer. Arlan Richardson, a professor at the Reynolds Oklahoma Center on Aging, believes that Rapamycin could eventually be the miracle anti-aging drug for humans. “It’s the best bet we have,” Richardon told CNN.

Researchers at the University of Washington’s Dog Aging Project have been testing Rapamycin on aging dogs. “[The heart] started to function better. It started to look like a more youthful heart,” said Matt Kaeberlein, co-director of the Dog Aging Project.

Two specific success stories in dogs have been Paola Anderson and Sarah Godfrey‘s 13-year-old white Pomsky and 13-year-old Pomeranian Sherman.

“It’s been remarkable,” Anderson told CNN. Speaking of Sherman, who had suffered from a debilitating stroke, Anderson said, “The third day after taking rapamycin, he could eat on his own. By the seventh day, he was walking on his own.”

Godfrey added, “Why not have your dog live longer if you can? We call Sherman and Momo our rapamycin babies.”

As of yet, there hasn’t been much Rapamycin testing in healthy humans. However, a test of 218 elderly volunteers found that it enhanced their response to the flu vaccine by 20%. The results of the study “raise the possibility that (rapamycin) may have beneficial effects” on the immune systems of elderly individuals, per the researchers.