One possible cause of low libido or hypoactive sexual desire disorder is an imbalance of testosterone. Testosterone is a hormone most often associated with men. But the ovaries and adrenal glands in women make testosterone too, just in much smaller amounts. And not unlike most hormones, testosterone levels fluctuate throughout the lifespan in response to feedback from other hormones in the body or hormonal medications. (For example, the progestin in combined oral contraceptive pills can lower testosterone.)
Lower sex hormones are universal during natural and surgical menopause, but the effects on the body vary; some women experience few symptoms while others suffer immensely.
Testosterone replacement therapy in women has been controversial and the Food and Drug Administration (FDA) has yet to sign off on its use in women for this purpose.
It's confusing because blood levels of testosterone don't necessarily parallel the level of sexual desire and there are active and non-active forms of the hormone. So deficiency is not easy to measure.
Gynecologists are not apt to mention testosterone therapy for low sexual desire because it hasn't passed muster with the FDA. Although there is lots of evidence to support testosterone use in women for sexual dysfunction, long-term studies are still needed for the FDA to give the stamp of approval. (The FDA is concerned about the effects of sex hormones on breast cancer and heart disease risk similar to that found with hormone replacement therapy that contains estrogen.)
Still, gynecologists can offer the testosterone that has a legitimate indication in men, but in a smaller woman-sized dose.
Pluses: One recent study examined the use of a testosterone patch in postmenopausal women not taking any other form of hormone therapy and found that it increased the number of satisfying sexual episodes (increases in sexual desire, arousal, orgasm, and pleasure). It is well tolerated with few side effects.
Minuses: It's not FDA approved so it can only be given "off label." Side effects include increased hair growth, acne, male-pattern baldness, enlarged clitoris, deepening of the voice and lower good (HDL) cholesterol. Periodic liver function tests might be required.