Another substance, called hexarelin, has shown a similar effectiveness at raising HGH levels. All are being researched intensively at this time but will be available surely as pharmaceuticals in several years, requiring prescriptions.

Another intriguing idea that has surfaced in regard to hormone research involves a hypothetical hormone that has yet to be discovered. The evidence for this undiscovered hormone is indirect.

It puts one in mind of the indirect evidence that led to the discovery of the planet Neptune in 1846. where observations had shown that there were perturbations (irregularities) in the orbit of Uranus (the favourite planet of our teenagers). A French mathematician and astronomer named Leverrier concluded that these perturbations were due to the gravitational effects of another - as yet undiscovered - planet that was out beyond Uranus. Leverrier calculated where this undiscovered planet should be to produce the observed gravitational effects on Uranus, and when it was searched for, the planet that came to be known as Neptune was found in the predicted location.

In a similar way, indirect evidence suggests that there is an as yet undiscovered hormone that may effect the decline in HGH levels as we age.

Research so far shows that this decline is not solely due to the effects of growth hormone releasing hormone (GHRH) and somatostatin. So quite possibly, some of this decline is due to the action of some unknown hormone.

Supporting this idea is the following train of thought. GHRH, produced by the body, works on a particular receptor site in effecting the release of HGH. Man made substances, however, such as GHRP 6, GHRP 2, and hexarelin, which stimulate HGH release as well, effect this release by working at a different receptor site. But there is no known hormone made by the body that works at this second receptor site.

The conclusion is obvious. If there is a receptor site, then it must be there for a reason: there must be a hormone produced in the body that does its work there - only it hasn't been discovered yet.