There is no question that hormones have powerful and widespread effects in the body. There is also no doubt of their decline as we get older.
Hormones are really chemical messengers which turn on/off genes which produce proteins that carry out specific duties. Testosterone, for example, stimulates tissue building and sex drive in both men and women while estrogen hydrates the skin and keeps the bones strong. In addition to the decline of production as we get older our receptors become less efficient at detecting what we do produce.
All of our systems respond to the decline in hormones. Testosterone drops, muscle tone and strength drop. Estrogen drops, bone density and skin elasticity drop. Thyroid levels drop, weight gain and fatigue increases. Therefore, Hormonal Replacement Therapy (HRT). Even before the current scare about prescribed HRT, many people were using natural hormones in individualized amounts aimed at bringing their levels up to those of a young adult.
Laboratory testing of blood done by your M.D. or a saliva test available in pharmacies and health food stores can help you know what is needed. While the blood test is the gold standard, saliva testing will show what is actually in your tissues, not just what is in the blood.
Men are not immune to "change of life." Mostly, andropause is due to the reduction of testosterone. Mood drops, bodies become doughy, cholesterol levels increase, muscle mass drops. Men become grouchy couch potatoes with little interest in romance. Many supplements have value. I like Andro-Edge which promotes natural testosterone production and herbs such as Chrysin and Tribulus. Damiana is an old traditional which many people still use. I think Indium-XL is also beneficial. Yohimbe is a natural version of a prescribed drug which brings back desire.
Others to consider are Human Growth Hormone, DHEA and supplements to support a sluggish thyroid gland. I think it goes without saying: a healthy diet, low alcohol or herb (you know what I mean) use combined with exercise will go a long way in bringing passion back to life.