Why Aging Women Need TestosteroneApril 2004
By Edward R. Rosick, DO, MPH, MS
Numerous studies show that maintaining youthful testosterone levels in males confers powerful anti-aging effects. Testosterone-deficient men develop abdominal obesity (pot bellies) and diminished muscle mass, along with a loss of sexual interest and performance ability. Low testosterone is also associated with heart attack, Alzheimer’s disease, osteoporosis, and depression.
While doctors are slowly recognizing the benefits of testosterone therapy for aging men, evidence that women also become testosterone deficient is largely ignored. Controlled studies show that slightly increasing testosterone levels in aging women restores sexual drive, arousal, and frequency of sexual fantasies. In fact, low testosterone levels in women of all ages seem to suppress libido and cause sexual dysfunction. Restoring youthful testosterone in women has been shown to improve mood and well being, and to provide many other health-enhancing benefits.
While expensive testosterone drug patches for women are available by prescription, safe and inexpensive natural approaches also can increase testosterone levels in women.
Testosterone in Men and Women
Although doctors have known that women produce testosterone, most mainstream physicians have believed that hormones like testosterone are not important for women. Only levels of the “female” hormones progesterone and estrogen were thought to have any significant bearing on a woman’s health and well being. Over the last decade, however, more and more evidence has been brought forth suggesting that testosterone is a very important hormone for women, especially in terms of staying fit, lean, and sexually active.
One of the most widely disseminated studies showing testosterone’s importance in maintaining a woman’s general well being and sexual functioning was published in 2000 in the New England Journal of Medicine.1
This randomized, double-blind, placebo-controlled study examined the effects of transdermal testosterone patches on 75 women aged 31 to 56 years who had undergone a hysterectomy and bilateral oophorectomy (removal of both ovaries). Hysterectomies, with or without an oophorectomy, significantly decrease circulating levels of testosterone. Over three consecutive 12-week periods, the women were given placebo, 150-mcg testosterone patches, or 300-mcg testosterone patches. The unequivocal result was that women who received 300-mcg patches showed significant improvement in sexual function, mood, and general well being.
Benefits for Women’s Sexuality
Fortunately for women all over the world, Dr. Susan Davis is one of those rare researchers who are examining the ways in which testosterone supplementation can benefit women, whether or not they have had the aforementioned surgeries. At the Jean Hailes Foundation, a not-for-profit organization in Australia dedicated to women’s health issues, Dr. Davis and her colleagues have been studying testosterone’s importance in women’s overall health. In a 1999 article in the journal Clinical Endocrinology and Metabolism, Dr. Davis offered a detailed report on testosterone replacement therapy in both pre- and postmenopausal women.2 In women who are postmenopausal or have had oophorectomies, judicious testosterone therapy has produced a direct and sustained improvement in sexual drive, arousal, and frequency of sexual fantasies. Dr. Davis acknowledged that treating women in their twenties and thirties with testosterone for low libido is controversial, but also stated that its use should not be discounted. According to Dr. Davis, testosterone supplementation can significantly benefit young and otherwise healthy women with low levels of testosterone who suffer from low libidos and sexual dysfunction.
In a more recent article published in 2001, Dr. Davis wrote that testosterone appears to be quite important in maintaining a woman’s energy level and sense of well being, regardless of her age.3 Low testosterone levels in pre- and postmenopausal women can diminish motivation, induce fatigue, and contribute to low libido. Even women in their twenties who are taking birth control pills may suffer from low testosterone and its effects, as oral contraceptives are known to lower testosterone levels. While studies show that testosterone supplementation in postmenopausal women who have not undergone hysterectomies and/or oopherectomies can significantly improve sexual drive, arousal, and frequency of sexual fantasies, no such studies have been conducted on pre-menopausal women.4 Dr. Davis states, however, that “it is the clinical experience of the author [Dr. Davis] that a subset of pre-menopausal women with sexual dysfunction and reduced circulating androgen [testosterone] levels significantly benefits from judicious parenteral testosterone replacement.”
Effects on Strength and Fitness
While it is known that women begin to gain body fat 10 years before they experience menopause, and that many women gain weight when taking birth control pills, doctors often overlook the role that testosterone can play in helping to ameliorate this weight gain. This is likely because most doctors are uninformed about the use of testosterone replacement therapy in women. In addition, some early studies, now viewed as flawed, linked elevated testosterone levels in women with abdominal obesity (the patients involved had multiple hormonal imbalances that certainly contributed to their obesity). More recent scientific studies, such as one reported in the Journal of Clinical Endocrinology and Metabolism, have shown that obese women given low doses of synthetic analogues of testosterone (nandrolone) lost more body fat and subcutaneous abdominal fat, and gained more muscle mass, than women given a placebo.5 The study participants followed a low-calorie diet but did not change their exercise habits; after nine months, those women taking nandrolone had lost twice the body fat and gained six pounds of lean muscle mass compared to women in the placebo group.
Deficiencies May Lead to Heart Disease
An intriguing report in the Journal of Women’s Health examined the hypothesis that testosterone deficiency is a key predictive factor for heart disease in aging women or women who have had hysterectomies.6 Cardiovascular disease is the leading cause of death in postmenopausal women. Women who have hysterectomies are three times more likely to develop cardiovascular disease compared to women who have not had one. Women who have hysterectomies generally receive estrogen replacement therapy but not testosterone replacement. The study author postulates that this treatment discrepancy is why the incidence of heart disease rises dramatically in these women, and concludes that “the data we have demonstrating cardioprotective effects of testosterone, together with what we know about the loss of testosterone production in both instances of oophorectomy with hysterectomy and in women whose remaining ovarian function has been compromised by hysterectomy, point to testosterone deficiency as a significant factor to the reported increased incidence of cardiovascular risk factors [in women].”
Does Testosterone Inhibit Breast Cancer?
Many researchers believe that high estrogen levels are a major risk factor for developing breast cancer, and some have postulated that high testosterone levels in women also may pose an increased risk for breast cancer.7 On the other hand, other researchers believe the association between high testosterone levels and breast cancer in some limited studies may reflect that testosterone and estrogen levels are highly correlated in women, as testosterone can be a precursor for estrogen synthesis. Multiple studies now show that testosterone may help guard women against breast cancer. A study in 2000 looked at the effects of testosterone and tamoxifen (a widely used chemotherapeutic agent for breast cancer) on breast cell stimulation.8 The study showed that breast cells exposed to estrogen showed cancer-like rapid growth, but showed significantly less growth when also exposed to testosterone. A more recent study published in 2003 also showed that testosterone significantly inhibits breast cell growth, leading the authors to conclude that “…androgens [testosterone] may protect against breast cancer, by analogy with P4 [progesterone] effects upon the uterus.”9