What is the most important gland in the body? The testes, right? No way! Not even the all-important testes can hold a candle to the hypothalamus. The testes get the glory, but the hypothalamus sits back in the shadows as the real master of all we hold dear as a male. As we'll show below, the hypothalamus governs just about everything that is worth governing.
Most men think of the hypothalmus as a structure that lies deep within the brain behind the blood-brain barrier. Well, that simply is not true. It is true that it is "tucked away" with the brain, but it is mostly in front of the blood brain barrier and has considerable exposure to chemicals and toxins. The most infamous of the toxins that can damage the hypothalamus are the so-called excitotoxins, MSG and aspartame for example. Excitotoxins are abundant, and more often that not hidden in most modern wheys and processed foods. Have you seen autolyzed yeast extract or hydrolyzed protein in an ingredient list? You can bet it's packed with excitotoxins.
Many health-conscious men expose their hypothalamus to multigram dosages of free glutamine simply out of ignorance. As I document in my link on Excitotoxins and Testosterone , this is a really BAD idea. These dosages are likely slowly damaging hypothalmic tissues and it's no wonder that probably 95% of low T men on the Peak Testosterone Forum have secondary hypogonadism: they have been unknowingly hammering their hypothalamus for years with small but significan dosages of these toxins.<
So I am hoping in this thread to encourage men to take care of this all-important gland and also point out some very interesting research that shows that the hypothalamus' importance actually extends far beyond just it's hormone-boosting properties: it appears to be a literal fountain of youth. Consider these functions of the hypothalamus:
1. Testosterone. Testosterone production does NOT begin with the testes: it begins with the hypothalamus. They hypothalamus sends a signaling molecule, GnRH to the pituitary, which then triggers the release of LH (Leutinizing Hormone), which in turn triggers the testes to create testosterone. The testes are actually third anything. And, yes, anything that damages or injures the hypothalamus will likely affect testosterone production and the whole chain of steroid hormones in men.
Furthermore, most hypogonadal men are secondary, meaning that men with hypogonadism have an issue with either the pituitary or the hypothalamus. I base that on the fact that the great majority of low testosterone men on the Peak Testosterone Forum are secondary and have an issue with either the pituitary or the hypothalamus. The fact that they are secondary is shown by the fact that Clomid works on so many of them and that their LH (leutinizing hormone) levels are low or lowish. When a man has primary hypogonadism, usually his LH is on the high side, because it is "working overtime" to try to stimulate the testes into a more normal testosterone output.
The primary points are this: the hypothalamus is ground zero for production of your testosterone and other steroid hormones (DHT and the estrogens) and there is evidence that the hypothalamus is often the problem area for most low testosterone men.
2. Thyroid Function. Many, many men are hypothyroid. Hypothyroidism affects general health, sexual function, energy levels and can lower testosterone. And, very analagous to the situation with testosterone, the hypothalamus is starting point for thyroid hormone production. It secretes thyrotropin-releasing hormone (TRH) which is turn triggers the more well-known TSH that is released by the pituitary and monitored by many doctors. Thus, hypothalmic dysfunction can affect thyroid function in a very similar way to how it can downgrade testicular function. (For some research showing this, see #22 on my link How to Increase Testosterone Naturally.)
3. Insulin Sensitivity. What does a huge percentage of heart disease and erectile dysfunction have in common? Insulin resistance. Prediabetes and diabetes are rempant here in the U.S. and probably affect about half of adults over the age of 40. And how these conditions take a toll on our sex life. (See these Links on Diabetes and Metabolic Syndrome for more information.) Most men know that the pancreas houses the beta cells that manufacture insulin and that diet and exericse play a major role in controlling blood glucose and insulin levels. However, what few men realize is that the hypothalamus plays just as pivotal of a role in insulin regulation.
As is true of so many things, the region above your neck is the master control center for most of your bodily functions, inclduing insulin sensitivity. Researchers showed this recently in an animal study where they fed the animals a high fat diet. Why did they feed them a high fat diet? Because, as I often point out, a high fat diet induces insulin resistance. This led to "a decrease in insulin-induced signaling and an increase in activation of a protein known as SK6 in the hypothalamus." 
Further evidence is shown by the fact that excitotoxins, which damage the hypothalamus, make animals fat in a number of research studies.. Excitotoxins accelerate weight gain in other ways as well by the way: they have been shown in several studies to stimulate the pancreas. Plus, diet drinks, most of which are packed with excitotoxins, also have been shown in study after study to lead to weight gain.  (The reasons for this are a little different, however, than hypothalmuc damage.)
4. Aging. Where is the Holy Grail of human aging? Scientists recently found that it lies in the hypothalamus. Already in animals they have increased longevity by 20% simply by controlling NF-kB within the hypothalamus.  It turns out that FN-kB is literally a dial that controls aging and it is all due to the fact that it acts on the hypothalamus.
Some experts think that life span can be extended somewhat in humans through this as well. And, althought it hasn't been tested in primates yet, I don't think anyone doubts that the hypothalamus is ground zero to human aging. And no wonder: it controls blood sugar/insulin control and our key hormones. It's hard to find anything more important than that, eh?
So there are four very good reasons to protect your hypothalamus. Keep in mind that science may even develop a reasonable anti-aging strategy that involves control of the hypothalamus in the next few decades. Do you want to be left out of the party because your hypothalmic tissue is lesioned and unresponsive??