We could not survive without hormones. They are among the most common and vital chemical messengers in the body. From head to toe, each moment of life, they signal cells to perform tasks that range from the ordinary to the extraordinary. Among their many roles, hormones help regulate body temperature, blood pressure, and blood sugar levels. In childhood, they help us "grow up." In the teen years, they are the driving force behind puberty. But what influence, if any, the natural decline in some hormones has on the aging process in middle and late life is unclear. Although a few proponents are convinced that hormone supplements can favorably alter the aging process and have advocated their widespread use, the scientific evidence supporting this premise is, for the most part, sketchy.

For more than a decade, the National Institute on Aging (NIA), a component of the Federal Government's National Institutes of Health, has supported and conducted studies of replenishing hormones to find out if they may help reduce frailty and improve function in older people. These studies have focused on hormones known to decline as we grow older:

• HGH (Human Growth Hormone)
• Tetosterone
• Estrogen
• Progesterone
• DHEA
• Melatonín

Heed The Warnings

The NIA recognizes that some hormone-like products are available over the counter and can be used without consulting a physician. The Institute discourages individuals from self-medicating with these products for a number of reasons. First, these products are marketed as "dietary supplements", and therefore are not regulated by the Food and Drug Administration (FDA) in the same way as drugs. This is an important distinction because the requirements for marketing a dietary supplement are very different from those that apply to hormones marketed as drugs. Unlike drug manufacturers, a firm selling dietary supplements doesn't need FDA approval of its products and doesn't need to prove that its products are safe and effective before marketing. Also, there is no specific guarantee that the substance in the container is authentic or that the indicated dosage is accurate. Because of these differing standards, hormone-like substances that are sold as dietary supplements may not be as thoroughly studied as drug products, and, therefore, the potential consequences of their use are not well understood or defined. In addition, these over-the-counter products may interfere with other medications you are taking

Source: National Instituto of Aging: NIA: http://www.medicinenet.com/script/main/art.asp?articlekey=60662