Sexual stimulation and erection begin in the brain when neuronal testosterone-receptor sites are prompted to ignite a cascade of biochemical events that involve testosterone-receptor sites in the nerves, blood vessels, and muscles. Free testosterone promotes sexual desire and then facilitates performance, sensation, and the ultimate degree of fulfillment.

Without adequate levels of free testosterone, the quality of a man's sex life is adversely affected and the genitals atrophy. When free testosterone is restored, positive changes can be expected in the structure and function of the sex organs. (It should be noted that sexual dysfunction can be caused by other factors unrelated to hormone imbalance. An example of such a factor is arteriosclerotic blockage of the penile arteries.)

The genital-pelvic region is packed with testosterone receptors that are ultra-sensitive to free testosterone-induced sexual stimulation. Clinical studies using testosterone injections, creams, or patches have often failed to provide a long-lasting, libido-enhancing effect in aging men. We now know why. The testosterone can be converted to estrogen. The estrogen is then taken up by testosterone receptor sites in cells throughout the body. When an estrogen molecule occupies a testosterone receptor site on a cell membrane, it blocks the ability of serum testosterone to induce a healthy hormonal signal. It does not matter how much serum free testosterone is available if excess estrogen is competing for the same cellular receptor sites.

Estrogen can also increase the production of sex hormone-binding globulin (SHBG), which binds the active free testosterone into a nonactive "bound testosterone." Bound testosterone can not be picked up by testosterone receptors on cell membranes. For testosterone to produce long- lasting, libido-enhancing effects, it must be kept in the "free" form (not bound to SHBG) in the bloodstream. It is also necessary to suppress excess estrogen, as this hormone can compete for testosterone receptor sites in the sex centers of the brain and the genitals.For many men, a safe and easy way to increase free testosterone is to prevent it from being converted (aromatized) into excess estrogen.

Based on the multiple deleterious effects of excess estrogen in men, aggressive actions should be taken to reduce estrogen to a safe range. To determine if estrogen levels are too high, men are encouraged to have their blood tested for estradiol. If the blood test results show estradiol levels are greater than 30 pg/ml, men should consider radical lifestyle changes, and/or taking an aromatase-inhibiting nutrient or drug.This goes for on or off cycle.

Restoring youthful hormone balance can have a significant impact on male sexuality.
You are attemping to get your FREE TESTOSTERONE : ESTRADIOL ratio to that of a 25 year old which is a ratio of 4 : 1.

When ever your on cycle and libido fails or is blunted think about what has been
written and how it may relate. But the main thing is this; control estrogen and you will
have full control of libido. Keep free testosterone up and estrogen down and everything else
will follow. It's as simple as that.