Human trials of the pill will begin within six months.
"This is the closest we are to a safe and effective anti-ageing drug that's perhaps only three to five years away from being on the market if the trials go well," said Professor Sinclair.
The work has drawn the attention of Nasa, which is considering the challenge of keeping its astronauts healthy during a four-year mission to Mars.
Even on short missions, astronauts experience accelerated ageing from cosmic radiation, suffering from muscle weakness, memory loss and other symptoms when they return.
On a trip to Mars, the situation would be far worse: Five per cent of the astronauts' cells would die and their chances of cancer would approach 100 per cent.
Professor Sinclair and his colleague Dr Lindsay Wu were winners in Nasa's iTech competition in December last year.
"We came in with a solution for a biological problem and it won the competition out of 300 entries," Dr Wu said.
The effects of cosmic radiation are not limited to astronauts.We're all exposed to it aboard aircraft, with a London-Singapore-Melbourne flight roughly equivalent in radiation to a chest x-ray.
In theory, the anti-ageing pill could mitigate any effects of DNA damage for frequent flyers.
The other group that could benefit from this work is survivors of childhood cancers.
Dr Wu says 96 per cent of childhood cancer survivors suffer a chronic illness by age 45, including cardiovascular disease, Type 2 diabetes, Alzheimer's disease, and cancers unrelated to the original cancer.
"All of this adds up to the fact they have accelerated ageing, which is devastating," he said.
"It would be great to do something about that, and we believe we can with this molecule."
The experiments in mice, from a team at the University of New South Wales, suggest a treatment for these issues is possible through a new drug.
While our cells can naturally repair DNA damage - such as damage caused by the sun - this ability declines with age.
The scientists identified that the call signalling molecule NAD+, which is naturally present in every cell in the body, has a key role in protein interactions that control DNA repair.
Treating mice with an NAD+ 'booster' called NMN improved their cells' ability to repair DNA damage caused by radiation exposure or ageing.
For the past four years, Professor Sinclair and Dr Wu have been working on making NMN into a drug substance with their companies MetroBiotech NSW and MetroBiotech International.
The human trials will begin this year at Brigham and Women's Hospital, in Boston.