Your body naturally makes growth hormone to help fuel growth during your childhood and to help maintain your tissues and organs throughout your life. Beginning in your 40s, your pituitary gland -- the pea-sized structure at the base of your brain where growth hormone is made -- slowly reduces the amount of the hormone it produces.

Some people believe the dwindling level of growth hormone is responsible for the frailty that typically comes with getting older. And that's prompted some who are concerned about growing old and losing independence to turn to injections of synthetic human growth hormone (HGH) to stave off the realities of old age. But there's little evidence to suggest human growth hormone is the Fountain of Youth.

One of the most important issues affecting men is prostate growth and prostate cancer. Prostate enlargement affects half of the male population by the age of fifty. The condition is known as benign prostate hypertrophy (BPH), which can eventually lead to prostate cancer. Some herbs like saw palmetto and gingko have been proven to help alleviate prostate problems in men.