Medical researchers have discovered a naturally occurring compound the human body produces that can speed DNA repair, combat disease, and may turn back the clock on aging.

The compound — called NAD+, which is present in all cells — plays a key role in regulating protein interactions that control DNA repair.

An international group of scientists predicts the team’s discovery of NAD+ will lead to a new drug to reverse aging, speed DNA repair, and even keep astronauts healthy on long space flights.

A leading member of research team — geneticist Dr. David Sinclair, whose team is based at Harvard Medical School and the University of New South Wales in Sydney, Australia — said the first human trials of a therapy based on the compound will begin within six months.

Twenty-five volunteers will be injected with a substance to verify its health and longevity benefits. If the trial turns out successfully, larger scale human trials will be conducted in the United States, Australia, and possibly other countries.