Men have heard about testosterone their whole lives, but women might not have stopped to consider testosterone’s role in their bodies. While testosterone is the main reproductive hormone in males, it is also made by women, though in much smaller quantities. Women make testosterone in their ovaries and adrenal glands.
The exact function of testosterone in women is not completely understood. However, testosterone is important in female sexual function. It contributes to the sexual maturation of the vulva and vaginal tissues and the brain. It also affects female sexual behavior, specifically desire and the arousal response.
Why is it low?
Testosterone levels can be low in women who have had both their ovaries removed, or whose ovaries do not function well due to any reason, such as chemotherapy. The testosterone levels also decline in women throughout the life span, such that the levels of women in midlife are lower than the ones noted in women in their 20s and 30s. Also, women with diseases affecting the adrenal glands can have low testosterone levels.
Sexual function in women
It’s true that low testosterone levels can sometimes impact female sexual function negatively, but that’s far from the whole story.
Female sexual function is a very complex issue. It is determined by many factors, including women’s physical and emotional health, the health of their relationships with their partners, their previous sexual experiences, history and trauma, and more. These factors all interact in a complicated way.
Women who are experiencing problems with their sexual function should therefore be evaluated by a medical expert with experience in this field, such as a gynecologist. These women should be assessed for all the factors that could potentially be impacting their sexual function, including testosterone.
Even though low testosterone levels can potentially impact female sexual function, the relationship between testosterone levels and female sexual function is far from linear or crystal clear. As a result, no specific testosterone level leads to a diagnosis of sexual problems in women.
This is further complicated because laboratory tests are not sensitive enough to measure women’s low testosterone levels. The lab results cannot reliably help clinicians differentiate low levels from very low levels in women. More-sensitive tests of testosterone levels exist but are not widely available.
Therefore, diagnosing sexual dysfunction in women should not depend on testosterone levels, because the levels are not very reliable in females. On the other hand, before prescribing testosterone therapy, health care providers should check testosterone levels to make sure they aren’t high.
If testosterone levels are low and the symptoms fit, providers might consider testosterone therapy in women. Testosterone therapy has been shown to improve sexual function in postmenopausal women who have low desire for sexual activities that is not otherwise explained by a medical or psychiatric condition. This has been demonstrated in multiple clinical trials.
Even though testosterone has been shown to be likely safe in clinical trials lasting about two years, the U.S. Food and Drug Administration (FDA) has not approved its use in women. The problem is a lack of data and uncertainty regarding testosterone’s long-term safety in women. The main concerns relate to the risks of cardiovascular disease and breast cancer. Therefore, in the U.S., testosterone therapy for women is used as an off-label medication. Doctors can legally prescribe medications off-label. The term “off-label” is used when a drug has scientific evidence to support its use for a condition but is not specifically FDA approved for that condition, at that dose or in that form.
However, many professional societies, including the International Menopause Society, support careful, monitored testosterone use in postmenopausal women to improve their sexual desire, as long as there are no other contributing medical or psychiatric conditions. The goal of treatment in these women is to get their testosterone up to the levels that are seen in younger women before menopause. Despite what many women and the media tout, testosterone use is not recommended for:
- Treating depression
- Improving bone density
- Improving muscle mass or strength
- Reducing body fat
- Enhancing general well-being
- Improving cognition
Once women are started on testosterone therapy, improvement in sexual symptoms — if it is going to occur — will take about four weeks, with maximum results in about 12 weeks. However, if there is no change in sexual function six months later, testosterone therapy should be discontinued, and other reasons for the sexual problems should be explored.
The how of testosterone therapy
There are multiple ways to receive testosterone treatment. Again, none of these is approved by the FDA for women. Testosterone is best administered on the skin because it has fewer adverse effects, especially on the liver or cholesterol. Testosterone therapy given via the skin also has less effect on blood pressure. One concern with oral testosterone therapy in men is increased risk of blood clots, which does not appear to be as much of a risk with skin application and is a theoretical risk in women.
There are different preparations available, such as creams and patches. Many health care providers use the testosterone preparations on the market approved for use in men — but at one-tenth of the dose. In general, testosterone from compounding pharmacies is overall discouraged or at least should be carefully and only cautiously considered. Custom-compounded drug preparations are not regulated by the FDA. There can be significant batch to batch variation in the amount of the active drug. Therefore, it’s possible to receive a lower dose, or worse still, a higher dose than intended. Purity of these formulations is also a concern. As such, these products can be unsafe for use.
Avoid testosterone pills because they can lead to liver problems and lower high-density lipoprotein (HDL) cholesterol — the “good” cholesterol. Testosterone injections given in the muscle can lead to very high testosterone levels and tend to be very painful. Injected testosterone that leads to high levels can cause rage, acne, excessive facial or body hair growth (hirsutism), and hypersexuality. Similarly, testosterone pellets and implants are discouraged because they, too, can lead to very high testosterone levels.
Before women start testosterone therapy, their health care providers should check baseline testosterone levels to make sure that they are not high to begin with. While on testosterone therapy, women should have testosterone levels checked once every six months. The idea behind checking testosterone levels is not to target a certain testosterone level for treatment effectiveness, but rather to make sure that testosterone levels don’t get too high.
When given in low doses as recommended, testosterone has minimal side effects, such as a mild increase in acne and body or facial hair growth in some women. However, excessive doses can result in loss of hair, enlargement of the genitals and voice changes. Such changes should be brought to the attention of a health care provider. More studies are needed to understand the risks associated with use of testosterone over the long term in women.
Ekta Kapoor, M.B.B.S.
Dr. Kapoor is the assistant director for the Mayo Clinic Center for Women’s Health, and a nationally recognized expert and speaker on the topic of menopause. Follow her on Twitter @ektasinghkapoor.