Testosterone Estrogen

Testosterone and estrogen are hormones with pivotal roles in sexual performance, fertility, cognitive function, and many of the physical changes associated with puberty. Testosterone is produced in relatively high amounts in men compared to women, while the reverse is true of estrogen. However, the balance between these two hormones may be just as important as the absolute quantities.

About Testosterone and Estrogen

Testosterone and estrogen are chemicals that are secreted into the bloodstream, allowing them to reach all the different tissues in the body. When they come into contact with a cell that has the proper receptor (an estrogen receptor for estrogen or an androgen receptor for testosterone), they can enter the nucleus of that cell and cause changes in gene activity.

Testosterone and Estrogen

The Testosterone to Estrogen Ratio in Men and Women

For men, testosterone levels are at their peak in young adulthood, when the testosterone-to-estrogen ratio is approximately 50 to 1. Starting around age 30, however, testosterone levels gradually decline. One reason for this change is that older men are more likely to have their testosterone converted to estradiol (a type of estrogen) by an enzyme called “aromatase.” Older men still have more testosterone than they do estrogen, but the difference is not as great as it was when they were younger. Furthermore, as the ratio of testosterone to estrogen begins to shift, the chance that estrogen molecules will bind to androgen receptors (normally used by testosterone) becomes more likely. The body then responds by producing less testosterone, which shifts the balance even more.

In addition to aging, factors like obesity, alcohol abuse and certain medications will increase the relative amount of estrogen in men. If estrogen levels increase too much, men can begin to develop symptoms of feminization. These symptoms include:

  • Development of breasts
  • Increase in body fat
  • Loss of muscle mass.

In women, estrogen levels are much higher than testosterone levels. However, the exact ratio changes based on signals tied to the menstrual cycle. During ovulation, testosterone levels increase, perhaps as a way of arousing sexual interest during peak fertility. If ovulation results in a pregnancy, estrogen levels increase, and continue to increase up until delivery. As women approach menopause, estrogen levels rapidly begin to decline, while testosterone levels drop off more gradually. This difference in how quickly estrogen and testosterone levels change also affects the ratio of the two hormones.

Restoring Balance

Medical options are available for restoring imbalances in hormone levels in people who are experiencing noticeable symptoms of a hormone imbalance. Men with too much estrogen, for example, may be given drugs that counteract estrogen, degrade aromatase or increase testosterone production. Because hormone balance can be so delicate, any treatment designed to modify hormone levels is best overseen by a doctor or medical professional.


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