The history of testosterone research dates back to the mid 1800's.  Since prehistoric times, medicine men, scientists and physicians have known that removal of the testicles would take away the vitality of men and beasts.  A German physiologist in 1849 did experiments in which he took four roosters, removed the testes in two of them and transplanted those testes into the abdominal cavity of the other two roosters. The two castrated roosters grew fat and lazy (a sign very consistent with loss of testosterone).  The two that were grafted with testicles remained every inch a rooster.   They crowed, they battled, they chased hens enthusiastically, and their bright red combs kept on growing.  The comb of the cocks is actually a sexual organ.

In 1934 a scientist isolated the testosterone molecule and illustrated the structure. For this research he received the Nobel Prize in 1935. Testosterone research accelerated following this period of time, and one is able to find more and more research beginning in 1935.

In 1951 it was discovered that testosterone can improve nitrogen balance and increase lean muscle mass.  This discovery is fundamental in understanding how testosterone can benefit cardiovascular disease through protein synthesis.  By putting a person into positive nitrogen balance, there is positive protein synthesis. With positive protein synthesis, the structure of the body (whether it be bones, ligaments or muscles, which are all made out of protein) can be repaired with ease when they are damaged.  Additionally, testosterone also enables the body to produce and synthesize the enzymes in the proteins that are necessary for the structural and functional integrity of these organs.

In 1960 another scientist discovered that testosterone can lower cholesterol.  The most significant discovery about the role of testosterone in protecting men against cardiovascular disease was published when the Department of Medicine at Columbia University in New York reported in May 1994 (Artherosclerosis and Thrombosis Vol. 14, No. 5) that low levels of free testosterone are a risk factor and correlate directly with degree of coronary artery disease in men.  A low testosterone level may lead to arteriosclerosis, said Dr. Gerald Phillips, and that testosterone may protect against arteriosclerosis in men through an effect on lipoprotein - HDL.  Administration of testosterone to men has been reported to decrease risk factors for heart attack.  Low testosterone is also correlated with hypertension, obesity and increased waist to hip ratio.

Recently, there appears to be an increasing interest in the aging phenomenon of the male.  For years, much has been written about the menopause of the aging female which occurs around the late forties and early fifties.  However, research has begun to focus on the “male menopause or andropause.  When the female menopause occurs there is a physiologic change to announce its arrival, the loss of menstrual periods.  In contrast, there is no obvious physiological event that takes place to warn a male when the andropause has arrived.  One must understand that when the andropause arrives there is a drastic drop of serum levels of free testosterone.  The rate of this drop is about 1.5 percent per year.  While the total testosterone of a male does not drop drastically, the free testosterone, which is the biological active part of the testosterone, does drop precipitously with aging.  In fact, a significant drop in free testosterone can occur as early as the early forties.  Some research has suggested that when a man becomes impotent, he dies about 20 years later.  Impotence is an alarming signal.  All the other organs degenerate in tandem with the degeneration of the male testes.

At 40 years of age, roughly 2% of the male population become impotent; at 50 approximately 5%; at age 60 18%; at 70 years 27% and at 80 years of age 75% are impotent.  Once a man becomes impotent he loses his drive for life, he has impaired erections, his muscles become thinner, mental acuity fades.  He frequently becomes depressed and has aches, pains and stiffness as well as decreased mobility.  In some cases, there is excessive perspiration similar to menopause in woman.

Studies have shown that men with higher testosterone levels live longer, healthier and maintain a higher sexual potency.  Recent studies also show that testosterone has the ability to stop the spread of breast cancer in females.  Additionally, for many years research has shown that testosterone has a protective effect against autoimmune diseases, which is why lupus and rheumatoid arthritis occur more predominately in the female and are rarely found in the male population.

Although testosterone replacement is essential, one must treat it with caution as dihydrotestosterone (a metabolite of testosterone) can accelerate prostate cancer growth. Therefore, before a male patient is placed on testosterone, his physician should obtain a prostate specific antigen test, which is called a PSA test. The PSA is a very sensitive test for the presence of prostate cancer. If the patient has prostate cancer, then testosterone replacement therapy is not indicated. Other than this, physiologic doses of testosterone replacement have absolutely no adverse side effect.  The interesting note here is that low testosterone can actually obscure the test results. Researchers from Beth Israel Deaconess Medical Center reported that prostate cancer might go undetected by two standard screening tests in men with low testosterone levels.

The best method of initiating testosterone replacement in 1997 is via the transdermal method, using natural testosterone rather than synthetic testosterone.  While synthetic testosterone (taken orally or by injection) for the most part causes hepatotoxicity (their use is not recommended, and has been replaced by the use of natural testosterone), the natural testosterone is delivered transdermally either in a gel form or by a patch applied to the skin and released into the body gradually.  Another way is implantation of testosterone pellets, which is also quite effective but involves a minor surgical procedure and is therefore not as favorable a method as the convenient gel or patch.

The understanding of Anti-Aging Specialists now is that testosterone levels may even be normal, but if they are on the low side of normal the patient still may have some deficiencies.  It is better to keep levels in an “ideal” range.  The goal is to maintain a total testosterone level at about 900-1200 ug/ml and a free testosterone level of about 30-40 ug/ml throughout one's lifetime.

While testosterone deficiency, or hypogonadism, affects an estimated one million men in the U.S., only 100,000 to 150,000 men are currently receiving testosterone replacement therapy. The most frequent causes of testosterone deficiency include tumors and other disorders of the testicles, pituitary gland or hypothalamus and Klinefelter's Syndrome.  Symptoms of testosterone deficiency include decreased energy, depressed mood and decreased libido.