Estrogen and sex drive

This review analyzed the role of estrogen therapy in increasing sexual function among prostate cancer patients undergoing androgen deprivation therapy.

Prostate cancer cells rely on androgens (hormones such as testosterone) to grow. Therefore, a common therapy used to slow prostate cancer growth is androgen deprivation therapy (ADT). ADT may effectively treat cancer by reducing the levels of androgens in the body. However, ADT is associated with multiple side effects, such as fatigue, weight gain, hot flashes, loss of bone and muscle mass, and most commonly a decreased libido (sex drive) and erectile dysfunction. 

Since ADT also reduces the levels of estrogen, and not just of testosterone, several early studies have suggested that estrogen therapy (drugs used to increase the levels of estrogen in the body) may assist in decreasing these side effects. For example, the areas of the brain that control male sexual behavior are known to contain many estrogen receptors (complexes on the surface of cells that respond to estrogen). It has been suggested that the decreased sex drive seen in men undergoing ADT could therefore be a result of low estrogen levels. The current review examined recent research exploring the benefits and risks of additional estrogen therapy for patients undergoing ADT.

Overall, several studies have shown that estrogen therapy may increase male sex drive. A small number of studies found that men on estrogen therapy during ADT were more sexually active than ADT patients not on estrogen therapy. One of the studies investigated found that normal libido (sex drive) was preserved in 60% of men receiving a certain form of ADT called anti-androgens, such as flutamide (Eulexin). Anti-androgens, unlike other forms of ADT drugs, do not decrease estrogen levels.

While estrogen may increase libido in some men receiving ADT, other studies have shown that estrogen therapy may also decrease the ability to reach an orgasm. In one of the studies reviewed, 91.7% of men were not able to reach an orgasm while on estrogen therapy. However, a second study found that 70% of men were still sexually active, despite the inability to reach an orgasm. Estrogen therapy was not found to have any effect on erectile dysfunction.

This review concluded that estrogen therapy may increase libido and sexual activity among men receiving ADT, thus improving their quality of life. However, estrogen therapy is associated with several risks, and larger controlled trials are needed in order to validate these results.

Most of the studies reviewed in this article involved only a small number of patients. No information was provided regarding the effect of estrogen therapy on ADT success (whether tumor response or recurrence rates differed with estrogen therapy). Aside from sexual function, estrogen therapy has both advantages and disadvantages. Estrogen may reduce the incidence of hot flashes and increase bone mineral density. However, estrogen also raises the risk of cardiovascular diseases, high cholesterol levels, blood clots and enlarged breast tissue in men.

Consult with your physician regarding the risks and benefits of estrogen therapy during ADT.