A drug that reverses ageing could be on the market in three years, scientists claim.

In early experiments, the drug nicotinamide mononucleotide (NMN) had a dramatic rejuvenating effect on ageing mice.

Researchers hope to begin testing the drug on clinical trial patients in the next six months.

Lead scientist Professor David Sinclair, from the University of South Wales in Australia and Harvard Medical School in the US, said: "The cells of the old mice were indistinguishable from the young mice, after just one week of treatment.

"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."


Image: Clinical trials on NMN are expected to start in the US this year

NMN works by boosting levels of NAD+, which helps repair DNA.

Accumulated DNA damage is a major driver of natural ageing and a primary cause of cancer.

The reduce level of NAD+ in the body with age means DNA is not repaired as efficiently.

Recent work highlighting the anti-ageing properties of NAD+ has led to numerous supplements being sold online - though there is little evidence small doses can ward off ageing.

Another potential benefit of the drug is being explored by NASA, who hope it could help send astronauts to Mars.

They believe there is potential NMN could shield astronauts from the effects of radiation on the long voyage to the Red Planet.

A NASA competition last year was won by Prof Sinclair's team.

The clinical trials are expected to start at Brigham and Women's Hospital in Boston, US, this year.