Of all the hormones at work in the human body, none has received more press from the widest array of interested parties than testosterone. Not only has it been the
focus of scientific journals with its effect on health, but it has also become central to any discussion regarding muscle growth, aging and the endocrine system. It
has even been libeled in feminist political tracts denouncing it as a "poison" which must be neutralized.
The truth is, testosterone plays an important role in all these areas. And with the exception of gender politics where hostility is touted as science, the interest it engenders is justified.
The bottom line is that testosterone is important for the health and well-being of both sexes, and its absence or decline is cause for concern. It is a sign of the times (aided by a relentless and fatuously PC media) that leads to a society where even a hormone can be politicized.
Although the female comes first to mind when we think of human cycles (e.g. ovulation), research in the biological sciences proves that men are not immune to the changing tides of nature. Men have cycles too, though not as dramatic. This fact is evident from the very first look at how testosterone functions in the male body, starting with blood level which tends to be higher in the morning and lower in the evening. However, any attempt at drawing a simple hormonal scenario would be misleading. Many factors (as well as other hormones) are involved in all aspects of human behavior. This is why despite lower nocturnal testosterone levels, most men are more romantically inclined in the evening than at breakfast time. And indeed as we look further we will discover a wide array of hormones involved in human sexuality for both genders.
Testosterone peaks in puberty and declines with age. It is produced in the testicles in men and in smaller amounts in the adrenal glands of both sexes. Women also produce some in their ovaries.
But it is in the testicles of the male, in the Leydig cells, where the lion's share is manufactured. In these specialized cells the cholesterol is converted to pregnenolone and that in turn is converted into testosterone. Testosterone produces the obvious male characteristics first apparent at the onset of puberty such as a deepening of the voice, beard growth, lean muscle tissue and sperm.
In both men and women testosterone works as an anti-depressant and boosts self-confidence. The sex drive of both genders involves a whole host of hormones and peptides in addition to testosterone such as DHEA, vasopressin, serotonin, dopamine, LHRH, PEA (phenylethylamine) and Oxytocin. All of these substances are in continual flux relative to one another like so many levels on a stereo equalizer as nature mixes and remixes the hormonal sexual music we dance to. To add to the complexity, our hormones, while affecting our behavior, are in turn affected by how we behave through all the phases of interpersonal contact - from first noticing someone and seeking eye contact, responding to verbal and nonverbal signals, right through to the pursuit, courtship and finally physical relations and emotional attachment.
Testosterone comes in two forms: bound and free. The amount of testosterone freely circulating in the blood is the vital number which determines the effectiveness of the hormone. Bound testosterone is free testosterone which has become trapped by a protein molecule such as albumin or globulin. Doctors have for a long time measured only the total testosterone level, which is not a very useful evaluation. The free form - i.e. the active stuff - may represent only 5 percent of the total figure, but that 5 percent can be explosive.
Testosterone is secreted in pulses by the body. A doctor cannot easily, whether by injection or oral supplementation, mimic nature's delivery system. Injections, not surprisingly, can produce unusual highs and lows. This pulsing release pattern explains the importance of having your testosterone levels checked not once but three times at 15- or 20-minute intervals and the results averaged. Both free and bound forms should be measured to produce a more accurate result. The morning is a good time since more of the hormone is likely to be circulating.
Paradoxically, although testosterone is associated with the sex drive and the hunt for a partner, it is also the "loner hormone." It drives a man to his sexual conquest but then it will also cause him to be emotionally separate from his partner afterward. All those other hormones are in the mix to balance out some of the negative effects of each individual hormone.
If testosterone predominates too much, the hormones which drive a man to seek a connection and attachment will be overwhelmed, and we end up with the surly bad-boy biker type -tattooed and cruising for some action but not interested in any deep conversation or long-term commitment. This could very well be nature's idea of spreading the seed as far, fast and wide as possible by moving on after each encounter. In popular culture such a figure is epitomized by James Bond or Clint Eastwood's The Man With No Name persona (probably better to escape child-support payments). Oddly enough, there is also evidence that testosterone contributes to making a man sensible and logical (another paradox!) Achieving success in life and vanquishing enemies enhances testosterone level while losing suppresses it.