n. The period in a man's life during which the production of testosterone begins to decline.
In nearly four decades as a therapist, Diamond has seen the interest in men's health — especially andropause — soar, partly because of the aging population.

One British study of 1,500 male patients tracked over 10 years found about 25 per cent of 40-year-old men are going through andropause, with the number rising to 70 per cent for men aged 70-plus.
—Marlene Habib, “Psychotherapist says men should tackle their mid-life changes,” The Canadian Press, April 23, 2002
Mid-life crisis, in which a man gloomily reviews his domestic and professional roles, looks forward without much hope and backwards with longing for his vanished youth, strikes remarkably early — between the ages of 35 to 45. Conversely, in the andropause the physical and mental symptoms follow the slow decline in the testosterone levels in the blood. It starts to erode male confidence at about 45-55, just in time to confirm all those unfounded fears of the earlier mid-life crisis.
—Dr. Thomas Stuttaford, “Men ageing badly,” The Times, September 24, 1998
1991 (earliest)
KING: Things are active?

Mr. SHARIF: Yes, things are going very well — I'm touching wood — and it all started happening about three years ago. I had come out of a very bad period of about 10 years. I think I went through what is called the 'andropause.'
—“Omar Sharif With a Fragrance 'For Women',” Larry King Live (CNN), May 09, 1991
This time of life has also been called manopause and viropause (where the vir- suffix comes from the word virility).