Australian researchers may have made a discovery that could keep older people limber for longer.

Scientists at Sydney's Garvan Institute say their research delivering small doses of testosterone directly to the liver may stop muscles wasting away in old age, ending frailty for the elderly.

Endocrinologist, Professor Ken Ho, says the public health implications could be incredible: “Given the scale of frailty in elderly population and the scale of dysfunction that arises as a result of protein wasting from a whole range of medical diseases which in our view is preventable.”

Many are well aware of the side-effects of testosterone treatments, but the Garvan researchers say that won’t be a problem.

“We have made the discovery that the ability of testosterone to build protein in the body works through the liver. And we tested this by exposing the liver solely to testosterone by taking a small dose of testosterone by mouth. This means that after absorption, the liver is the first organ exposed to testosterone,” said Prof Ho, “the liver then metabolises the testosterone so that none of this hormone spills into the peripheral circulation. And as a result of that, all body tissues and organs apart from the liver do not get exposed to the hormone.”

The team have completed a proof of concept on a group of post-menopausal women; they now say a larger study is needed to investigate the long term effect of oral testosterone on muscle mass and function. The applications could be truly vast, with many conditions causing a vicious cycle of muscle wastage, frailty and immobility for the elderly.

The new research has been published in the European Journal of Endocrinology.