If you run blood tests on a man over 50 years old, you will discover that his testosterone level is well below where it was when he was 40. For every ten men in this age category, two or three will have below-normal testosterone readings.
如果替五十歲以上的男士抽血檢驗，會發現他們的雄激素（睪酮素）比四十歲時下降許多，其中更有二到三成的人，其睪酮素濃度會低於正常值。