What Testosterone Actually Does for Women After 40 — And Why Your Doctor Probably Never Mentioned It

When women come to me having already been through one or two other hormone therapy providers, the pattern I see most often is this: they are on estrogen, they may be on progesterone, and their symptoms are partially better but something still feels off. The energy is not quite back. The motivation is flat. The libido is absent in a way that feels disconnected from how they feel about their relationship. The brain is clearer but not sharp. They are better, but they are not themselves.

In the majority of these cases, testosterone has never been discussed, tested, or offered. And in the majority of these cases, that omission is exactly why the protocol is incomplete.

Testosterone is not a male hormone

This is the framing that has done more harm to women's health than almost any other piece of medical mythology. Testosterone is produced in the ovaries and the adrenal glands throughout a woman's entire reproductive life. It is the most abundant biologically active gonadal steroid in women's bodies, present in higher concentrations than estradiol at virtually every stage of life. It governs libido, yes, but also motivation, competitive drive, cognitive sharpness, physical vitality, muscle integrity, bone density, and the fundamental sense of energy and presence that so many perimenopausal women describe losing and cannot explain.

Testosterone levels in women peak in the mid-twenties and decline steadily from that point forward. By the time a woman reaches menopause, her circulating testosterone levels are up to 50 percent lower than they were in her younger adult years. That decline is gradual and quiet, which is precisely why it goes unaddressed. There is no dramatic, undeniable signal like a hot flash to force the conversation. Instead the loss of testosterone announces itself in ways that are routinely attributed to stress, aging, relationship issues, depression, or simply being too busy. The flat libido. The disappearing motivation. The sense that things that used to light you up no longer do. The difficulty building or maintaining muscle despite consistent effort. The fatigue that sleep does not fully resolve.

None of these are inevitable. Many of them are treatable.

What the research actually shows

The evidence on testosterone for women is substantially stronger than most physicians have been trained to believe. A 2024 study published in the Archives of Women's Mental Health evaluated over 500 women who were already on hormone replacement therapy but continued to experience low mood, brain fog, and reduced sexual desire. After adding low-dose transdermal testosterone, 47 percent reported improved mood, 39 percent reported improved cognitive clarity, and 52 percent reported improved libido. These were women who were already on estrogen and progesterone and still not fully well. Testosterone was the piece that completed the picture.

A comprehensive review examining data from nearly 8,500 women across studies from 2019 to 2024 found significant improvements in sexual desire with testosterone therapy, with 2024 randomized controlled trials additionally confirming mood and cognitive benefits including reduced fatigue and improved vulvovaginal health. The British Menopause Society and the International Menopause Society both endorse testosterone for postmenopausal women when other interventions have been insufficient, with side effects occurring in fewer than five percent of patients at physiological doses.

Beyond libido: what testosterone does for your brain, bones, and body

The conversation about testosterone for women has been almost entirely limited to sexual function, which has done the research a serious disservice. Testosterone's role in women's health extends across every major body system.

In the brain, testosterone supports the pathways involved in motivation, focus, and drive. Its decline is associated with cognitive slowing, difficulty concentrating, reduced initiative, and the flat affective state that many women describe as feeling like a lesser version of themselves. In men, testosterone deficiency is formally associated with fatigue, depressed mood, and cognitive impairment. The biology in women is not meaningfully different, yet women are rarely offered the same evaluation or the same treatment.

In bone, testosterone acts directly on androgen receptors distributed throughout skeletal tissue and supports cortical bone strength, the dense outer layer of bone that provides structural integrity. Women with lower testosterone consistently show greater rates of bone loss and reduced bone mineral density, making testosterone a meaningful part of any comprehensive approach to skeletal protection, alongside estrogen and progesterone.

In muscle, testosterone supports lean mass preservation and the body's response to resistance training. The loss of muscle that many women experience in their forties and fifties, the weight that appears despite unchanged eating habits, the frustrating inability to get stronger despite consistent effort, is substantially hormonal. And testosterone is a significant part of that picture.

A peer-reviewed 2022 paper published in the Journal of Personalized Medicine reviewed 80 years of safety data on testosterone use in women and found growing evidence supporting its use for sexual function, osteoporosis prevention, and brain protection, while noting that millions of women are suffering in silence with symptoms that could be addressed with physiological testosterone therapy.

The FDA regulatory gap that has failed women for decades

Here is the part of this story that should make every woman angry. There is no FDA-approved testosterone formulation for women in the United States. Not one. Men have access to more than 30 FDA-approved testosterone products. Women have zero. Every male formulation carries dosing appropriate for male physiology, roughly ten to twenty times higher than what women need. This regulatory gap means that prescribing testosterone for women requires off-label use, which makes many physicians uncomfortable despite the existence of substantial and growing evidence for its efficacy and safety at physiological doses.

As one physician put it plainly: one in five men are diagnosed with hypogonadism, a condition where their bodies stop making enough testosterone. Nearly all women experience the same hormone decline if they live long enough. Men have more than a dozen FDA-approved formulations, but when a woman asks for the same hormone, her physician has to say there is no FDA-approved dose for you. That disparity is not based on science. It is based on the historical failure to study and approve therapies for women's hormonal health with the same rigor applied to men's.

Women in Australia, the United Kingdom, and many European countries have had licensed testosterone preparations for female use for years. American women are largely left without them through their standard medical care, pushed toward either suffering or compounded preparations that exist precisely because the regulatory system has not caught up to the clinical need.

If you have been on estrogen and progesterone and you still feel like something is missing, there is a strong possibility that something is testosterone. It is not a minor addition to a hormone protocol. For many women it is the piece that makes the whole thing work.

Dr. Anat Sapan, MD, is a board-certified OB-GYN and menopause specialist practicing telemedicine in California, Florida, New York, and Illinois. To book a complimentary discovery call, visit doctoranat.com.