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Estrogen, the main sex hormone in women, plays a bigger role in male libido than previously recorded.

The study found that reducing estrogen in men undergoing treatment for low testosterone resulted in a drop in libido and an increase in body fat, even as testosterone levels improved.  This new research is published in the New England Journal of Medicine.

The findings surprised researchers, who have believed that testosterone mainly caused men to have stronger sex drives than women.  While it’s known that the body converts some testosterone into estrogen and that the hormone declines in men with low testosterone, researchers didn’t fully understand estrogen’s role in male sexual desire.

Both sexes require the opposite gender hormone to have adequate libido.  While there have been clues that estrogen as well as testosterone influence male sex drive, there have been few definitive studies.

In the study, researchers studied a group of men ages 20-50 that were given treatments to suppress production of all reproductive hormones.  Half of the men were then given a testosterone boosting gel or a placebo; While the other half received the testosterone gel along with a drug that lowered the production of estrogen.

The researchers found that testosterone was the main hormone involved in lean body mass and muscle strength.  Estrogen played a bigger role in fat accumulation.  Although low testosterone did cause a decline in sexual desire, those getting the estrogen-suppressing drug saw a greater drop-off.

For an appointment or consultation with Dr. Gary Bellman, please contact the office or call 818-912-1899