There are all sorts of products available to consumers that promise anti-aging properties, from skin tightening creams to health supplements. But what if you could swallow a pill and actually reverse aging on the cellular level?

A real fountain of youth might be just around the corner, thanks to researchers at Australia's University of New South Wales (UNSW). They have discovered a protein complex that allows cells to repair DNA damaged from either radiation or old age, and it's so promising that it has garnered interest from NASA as a way of keeping astronauts healthy during long space flights, reports MedicalXpress.com.

"This is the closest we are to a safe and effective anti-aging drug that's perhaps only three to five years away from being on the market if the trials go well," said David Sinclair, lead author on the study, which was published in the journal Science.

Our bodies must constantly work to repair our DNA, which can be damaged even from regular exposure to the sun, among a host of other things. But this healing process slows significantly as we age. The tincture discovered by the UNSW researchers works by boosting this natural system.

The drug was devised after scientists identified that the metabolite NAD+ plays a key role as a regulator in protein-to-protein interactions that control DNA repair in our cells. They then developed a NAD+ booster, called NMN, that has already been shown to repair DNA damage caused by radiation exposure or old age in mice.

"The cells of the old mice were indistinguishable from the young mice, after just one week of treatment," said Sinclair.

Because the drug boosts an entirely natural system already at play within our cells, scientists are optimistic that there will be few health concerns with its use. In fact, human trials of NMN therapy are set to begin within six months.

Why NASA is on board

Sound too good to be true? Not if NASA has anything to say about it. The space agency is currently in the throes of planning manned missions to Mars and (eventually) to other far-flung corners of the solar system, but one of their chief concerns has to do with radiation exposure. Scientists calculate that 5 percent of an astronaut's cells should die just from radiation exposure on a trip to the red planet. An astronaut's chances of developing cancer approaches 100 percent on such a mission.

If damage from this radiation exposure can be mitigated or even reversed by NMN, it could make long-distance space missions far more feasible. Of course, the drug would be just as useful here on Earth too, especially for those who have experienced high levels of DNA damage from chemotherapy or radiation exposure — or for anyone who just wants to feel young again.

As it's said, youth is wasted on the young. But maybe in just a few years' time, that won't have to be the case anymore.