The existence of the male menopause has been called into question by a study designed to test the benefits of male hormone replacement therapy (HRT). 

Experts in Finland were forced to stop their research when tests on men who said they were going through the male menopause showed that they were not.

The findings, which will be released today at the European Congress of Endocrinology in Glasgow, will be of concern to drug companies, who have spent millions developing male HRT products including gels, pills and injections.

In recent years, a growing number of doctors has argued that middle-aged men experience a sudden fall in testosterone. More than half of men in their 50s are thought to suffer lethargy, lack of interest in sex, mood swings and hot flushes, which have been blamed on the male menopause.

Initially, the Finnish study was intended to treat 200 men from Turku, who were going through the male menopause, also known as the andropause, with replacement testosterone.

Responding to a questionnaire sent out to 30,000 men aged between 40 and 70, about 2,500 reported a high level of "andropausal" symptoms and 1,800 agreed to undergo tests.

However, just 250 were found to have low testosterone and, once other medical causes were excluded, this fell to just 37 - a figure so small that any results would not be judged statistically significant. The trial was abandoned.

Dr Antti Perheentupa, of the University of Turku, said: "This seems to indicate that a genuine andropause may be quite rare, and certainly not as common as people imagine."

However, Dr Malcolm Carruthers, of the Society for the Study of Androgen Deficiency, gave a warning against ruling out the existence of the male menopause. He said the Finnish study was looking for symptoms to correspond to specific levels of testosterone in the blood, which was not reliable.