Spanish explorer Juan Ponce de León famously journeyed to the Americas in search of the Fountain of Youth. If he were still alive today, he might have been able to simply visit his pharmacist instead.

A potential anti-aging drug that is already commercially available for the treatment of type 2 diabetes, called metformin, is soon set to begin clinical trials to see if it can also expand the human life span, reports the Express.

Initial tests on some animals, such as one study of the drug's effects on worms, suggest that humans could live healthily well into their 120s if the effects are shown to be similar. Metformin could literally be a miracle drug-- the Fountain of Youth in pill form. It could change medicine in a way not seen since the discovery of antibiotics. That is, assuming the trials are a success.

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Early optimism is high. Since metformin is commercially available for the treatment of diabetes, several extensive studies about its effects are already available; the hype is not merely based on a simple worm study. For instance, last year a study of more than 180,000 people showed that those being treated for diabetes with metformin lived longer than a healthy control sample. That is worth reiterating: Patients being treated for diabetes lived longer than otherwise healthy people.

Other research has shown that metformin could also help to directly treat conditions such as Alzheimer's, heart disease and even cancer.

"I have been doing research into aging for 25 years and the idea that we would be talking about a clinical trial in humans for an anti-aging drug would have been thought inconceivable," said Gordon Lithgow of the Buck Institute for Research on Aging in California. "But there is every reason to believe it's possible."

The clinical trial is called Targeting Aging with Metformin (TAME), and it will be conducted by the U.S. Food and Drug Administration. Researchers are looking for 3,000 people in their 70s and 80s who either have or are at risk of having major diseases, and the trial should last from 5 to 7 years.

The drug has already been in use for over 60 years for diabetes patients, so scientists have a pretty good idea of how exactly it works. For instance, metformin is known to make our cells better oxygenated, and its easy to imagine how better oxygenated cells can have a positive effect on the body.

"We lower the risk of heart disease, somebody lives long enough to get cancer. If we reduce the risk of cancer, somebody lives long enough to get Alzheimer's disease. We are suggesting that the time has arrived to attack them all by going after the biological process of aging," said Stuart Jay Olshansky, one of the researchers involved in the project.

If all goes well, then age 70 could soon become the new 50. Age 100 could be the new 80, and so on. Better yet, we can age in a healthier fashion, free from many of the debilitating diseases that make living to older ages undesirable. It won't be an immortality pill, but it might be the next closest thing.