The medical establishment has long refused to accept that the male menopause or andropause exists. This blank denial flies in the face of over 50 years of evidence that reduced activity of the hormone testosterone can have a huge effect on a man's health and potency. Around the age of 50, but sometimes much earlier or later, action man may turn into inaction man. From being a positive, bullish and outgoing person, he changes to a negative, depressed bear with a sore head; a disaster in both bedroom and boardroom. What is the male menopause and does it really exist? Low testosterone activity is common in men over the age of 40. It causes loss of energy, libido and potency, hot flushes, irritability and other symptoms. It is often confused with the mid-life crisis. Carefully monitored use of Testosterone Replacement Therapy may be an important part of the preventative medicine of the future.