By Stuart Macdonald

SCIENTISTS at a Scots firm have devised a miracle gel to pep up middle-aged men's sex lives.

The revolutionary treatment Tostran will also combat other effects of lack of testosterone, such as flabbiness and hair loss.

It is aimed at men over 40 who suffer from hypogonadism, a condition which causes reduced libido, erectile dysfunction, baldness, weight gain, and lethargy.

Makers ProStrakan, based in Galashiels, Selkirkshire, estimate six to 12 per cent of men over 40 have the condition, rising to 91 per cent of men over 80.

Men experience a natural decline in the production of the male hormone testosterone from the age of about 30.

The colourless gel, available on prescription at a cost of NHS to the NHS, is applied to the shoulders, upper arms or abdomen.

It releases a synthetic version of testosterone slowly into the bloodstream and normal levels are restored in most men within hours.

The gel's launch in the UK came after it was piloted in Sweden and became a huge hit with Scandinavian men.

Previous testosterone replacement therapies have had unpleasant side-effects such as acne, headaches and even enlarged breasts.

Dr Wilson Totten, chief executive of Prostrakan, said they hoped to soon launch the product across Europe and America.

He said: "Tostran represents a high-potential, high-value opportunity for us and its UK launch is a major milestone in the group's development."