Some women are understandably skeptical when I mention testosterone as a possible aid for perimenopausal loss of libido. They envision themselves developing a deep voice and facial hair, sporting the shoulders of a fullback, and demonstrating aggressive behavior. When testosterone is given in dosages that are too high, or if a woman has trouble tolerating the synthetic form of this hormone, side effects can indeed occur. Testosterone replacement in women should be carefully weighed beforehand and monitored after therapy begins.

As ovarian function changes and hormone production declines, testosterone levels in the female body also drop. We don’t see a sharp plunge in testosterone levels, in fact, testosterone drops only slightly in most perimenopausal women. But when the ratio between testosterone and estrogen and progesterone goes out of balance, its effects may either seem more potent or sharply diminished.

It was once believed that taking testosterone would kick anyone’s libido into overdrive, but we now know that for women, without estrogen and progesterone present in the proper proportions, adding testosterone alone doesn’t do much at all. Women with polycystic ovarian disease, which causes elevated testosterone levels, do not report excess libido, a finding that is sometimes cited as evidence that testosterone is ineffective in treating suppressed libido. However, mat view takes only a piece of the picture into account, ignoring the relationship between testosterone, estrogen, and progesterone.

Like estrogen and progesterone, testosterone is available in natural and synthetic forms. Natural testosterone, which is chemically identical to the testosterone your body produces, can be an option for women who have trouble tolerating the potent synthetic, methyl testosterone. Estratest, which combines estrogen with methyl-testosterone, can negatively affect cholesterol and changes liver function in some women.

In the past, testosterone was administered in doses that were much too high for women. These high doses created problems such as facial hair growth, deepening voice, and in some cases irritability. Small doses of testosterone (as little as 0.1 mg of natural testosterone cream can be applied to the hands twice a day with good results), appropriately balanced with estrogen and progesterone, can rekindle sex drive as well as help build muscle and bone. Women have told me that adding testosterone to their HRT regimen boosted their energy levels or, as some put it, added “a spark” or “life force energy.”

Testosterone doesn’t help all women. Judith told me that several months before; she took testosterone for two weeks to help stimulate a waning sex drive. She wasn’t sure if testosterone had an effect on her libido, but she noticed a change in her mood very quickly. She felt, as she described it, “terrible.” “After two or three days, I was much more irritable. Irritability doesn’t encourage more lovemaking.”

As it turned out, Judith was taking more synthetic testosterone than she probably should have. The fact that she was drinking daily may also have contributed to her fatigue and indifference toward sex. Changes in sex drive can often be hard to sort out, where the hormonal component begins and ends, and what role lifestyle or depression may play. Her moods stabilized to some degree after she stopped taking synthetic testosterone, but she was still troubled by her lack of sexual desire.

First, I thought it made sense to measure her current testosterone level in saliva, along with her estrogen and progesterone levels. If her level of testosterone turned out to be below normal, she could consider natural testosterone, since she hadn’t responded well to the synthetic testosterone. I also recommended that she cut back on the alcohol by alternating one glass of sparkling water with every glass of wine she drank; to be sure alcohol wasn’t a contributing factor to the change in her libido.

Judith’s testosterone levels measured 15 pg/ml, which is below the normal range. She was leery of taking testosterone again, but after I explained that the natural form of the hormone is well tolerated and does not produce the side effects associated with the synthetic, she decided to try natural testosterone in vaginal cream form. She used it twice a week for a month and felt a subtle change in her level of desire. “I feel more in balance now,” she told me when I saw her next. “I don’t have that strange apathy when it comes to sex that I had for months. I’ve found warmth and closeness with my husband again.”

Judith also said she thought that drinking less helped her moods and perhaps her libido as well: “It was a good decision to cut back. The amount? I was drinking had crept up without my realizing it. I’m not going to bed with that cloudy feeling in my head from a few glasses of wine anymore. Overall I feel more alert and alive.”