The scientists have said much more research would be required before metformin can be approved as an anti-ageing compound in humans.

Scientists have long been interested in metformin, a widely prescribed drug used to treat Type 2 diabetes, for its potential to delay aging.

Metformin is the main first-line drug used to treat type 2 diabetes, but a new study on monkeys suggests it could one day be used to slow brain aging, too. Hints of the drug's anti-aging affects have been seen previously in retrospective studies on people who take the drug for diabetes, and also in worm, fly and rodent studies.

Monkeys that received metformin daily showed slower age-associated brain decline than did those not given the drug. Furthermore, their neuronal activity resembled that of monkeys about six years younger (equivalent to around 18 human years) and the animals had enhanced cognition and preserved liver function.

Scientists from the Chinese Academy of Sciences (CAS) have made a groundbreaking discovery about aging, raising the question: is it reversible? Their research sheds light on how metformin, a common medication for type 2 diabetes,

Scientists in China have found evidence in monkeys that metformin can reliably slow down the brain's aging process.