Bernard Collen first noticed unusual symptoms 11 years ago. He was working as a buyer at London's Covent Garden flower market, a demanding job which required him to get up at 0230 every morning.

He told BBC News Online: "I was feeling tired, run-down and very irritable on most occasions. I had also lost my libido. I put it down to my job.

"But it was primarily the mood swings that were the biggest strain on my wife and my step-son as well.

"I didn't know what to do, or where to turn."

He thought a doctor would simply put the problems down to his age or his job.

And he admitted: "Usually the answer men seek is an 18-year old blonde."

Crucial appointment

He was still uncertain what to do when his wife read a newspaper article about the male menopause, and contacted Dr Malcolm Carruthers, chairman of the newly formed Andropause Society.

"He invited me to come along and have a blood test. He then suggested I could benefit from treatment, but he said we should take it one step at a time.

"I started on testosterone capsule. And within a couple of weeks, it felt like a great weight had been lifted. I became much more assured rather than aggressive."

Before the treatment, Mr Collen, 54, said he was going "round and round in circles", unable to make decisions in a very pressurised job where fast decisions were required.

He added: "A bonus was that my libido came back."