As much as we have learned about how the brain and body work together for sexual desire and appetite, there is still an incomplete understanding of the role of our sex hormones in fueling sexual desire. We know that it is common for some people to lose their desire for sex as they get older and their hormone levels drop. For sure, the pharmaceutical industry is banking on men thinking that their low sex drive is due to low T. But is this the answer?

What role does testosterone play in sexual desire and libido?

Testosterone is often thought of as the hormone that brings vigor and motivation to life. It works on the body to increase muscle mass and red blood cells, but also increases overall drive and competition. We know that when testosterone levels drop too low – for either men or women – they not only lose their sex drive and desire, but they also can become quite fatigued and even depressed. So then replenishing the testosterone should do the trick and bring back that sex drive, right? The answer is “yes”, and “no”.

Testosterone does not work alone.

Interestingly, doctors are finding more and more that testosterone doesn’t work alone when it comes to mood and sexual desire. Perhaps one of the most striking examples of this is in men receiving testosterone supplementation at the same time as receiving aromatase inhibitors to prevent the conversion of that testosterone into estrogen. There are actually some men who find that their testosterone levels are boosted to normal levels while their body’s production of estrogen is dialed way down – and after a certain drop in estrogen levels, their sexual desire disappears. If those same men are allowed to have conversion of their testosterone to estrogen and their estrogen levels rise to a certain point – bam! – their sex drive comes back.

Does Estrogen hormone work for sexual desire?

This question is a little trickier to answer since estrogen is made from testosterone – so very few people have estrogen in their bodies without testosterone. Even in women after menopause who are only receiving estrogen replacement, there is still testosterone being produced from the adrenal glands and other tissues. We do know, however, that some young women who take birth control pills have their sex drive completely disappear when their free testosterone levels drop as I described in this article. So it appears that estrogen alone is not the answer, although we still are unsure about the effects of synthetic estrogens (like the ones found in birth control pills) on the brain versus natural estradiol.

Estrogen is an important player in sex drive – but not alone.

This tells us that there is probably a combination of estrogen and testosterone working together to create sexual desire. Our hormones are always trying to balance out, and they are in constant communication with each other at the level of the brain as well as at the cellular level. Sex drive and sexual desire are complex and also involve a great deal of psychological factors as well, including how a person views sex, how they feel about themselves sexually, and how they view their partner and their sexual interactions with their partner. So despite the pharmaceutical industry looking for that one magic bullet for sexual desire, ultimately it’s going to come down to a combination of factors – even with hormones.

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