It does little good, for example, to slow the general aging process if you neglect certain aspects of cardiovascular health and die prematurely of a heart attack. There is good evidence that the decline of some of these substances is a cause, rather than just an effect, of the aging process. Melatonin is a very important hormone that declines with aging, but can be replaced orally. Some scientists believe that melatonin is the master hormone of aging, with the decline of melatonin signaling other hormones to accelerate the aging process. Most of the evidence suggests that this is only partially true.
Growth hormone is an important hormone that declines with aging.
It can be replaced by direct injection, but a far less expensive way that works for many people is to use growth hormone releasing agents stimulate the natural release of growth hormone. DHEA and pregnenolone can be replaced by taking supplements containing these hormones. It is important, though, not to take too much DHEA unless you are under medical supervision. MAO-B destroys dopamine and other important brain chemicals. Low doses of the prescription drug deprenyl will raise dopamine levels and inhibit the activity of MAO-B. Deprenyl may protect critical brain cells from damage if it is taken along with a broad spectrum of antioxidants.