A cure-all for the “male menopause” is to be launched today by a Scottish company in the form of a synthetic testosterone gel that can be absorbed through the skin.

Tostran is a prescription gel aimed at men over 40 who suffer from “hypogonadism” – a condition whose main symptoms include baldness, weight gain, lethargy, irritability, reduced libido and erectile dysfunction.

ProStrakan, which is marketing the drug, claims that up to 12 per cent of men over 40 and 91 per cent of men over 80 suffer from the condition, yet few ever seek medical attention.

Testosterone is a hormone produced by the testicles and is responsible for the development of male sexual characteristics. It maintains muscle bulk, ensures adequate levels of red blood cells as well as bone growth and sexual function.

Men over the age of 30 experience a natural decline in their body’s production of testosterone.

In tablet form, testosterone is broken down by the stomach so a gel is preferable to the only alternatives – regular injections or an implant. Patients rub the gel over themselves once per day and absorb the testosterone through their skin.

Wilson Totten, chief executive of ProStrakan, the Galashiels-based group behind the product, forecasts peak sales of Tostran could reach $150 million (£76 million) a year.

He described the UK launch of the product as a “very important step” for the company and said it would be followed by a roll-out across Europe later this year and the US in 2009.

The company bought the licence to use the technology for Tostran in 2004. “Testosterone replacement therapy” is becoming increasingly popular in the US, where it has become a $500 million market, although some studies have linked it to an increased risk of prostate cancer.

In the European Union, the market is currently worth singnificantly less, about $80 million, but it is growing fast alongside the Continent’s ageing population.

As well as men suffering from hypogonadism, Tostran is also being targeted at type 2 diabetics who may suffer similar problems.

ProStrakan, whose other products include Sancuso, a skin patch designed to relieve vomiting in chemotherapy patients, and Rectogesic, an ointment for chronic anal fissures, reported full-year losses of £17.3 million for 2006, down from £18.1 million last year.

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