Women, Testosterone Is Your Most Abundant Sex Hormone. Almost Nobody Measures It.
A new patient in her early fifties came to see me a few months ago, already six months into estrogen and progesterone and frustrated. The hot flashes were gone. The sleep was better. But she described herself as flat. She was lifting three days a week and getting nothing back for it. Her drive was gone, at work and at home. She told me she felt like a competent, tired stranger doing an impression of herself.
She had a thick chart. Thyroid, iron, B12, vitamin D, a full metabolic panel, estradiol, FSH. In fifty-one years, nobody had ever drawn a testosterone level on her.
That is the standard of care for women. Most doctors will not test testosterone even if the woman specifically asks for it.
The Number
Here is the fact that surprises most women: testosterone is the most abundant sex steroid in a woman's body. Measured by concentration, women circulate substantially more testosterone than estradiol across nearly the whole of adult life. The ovaries and the adrenal glands make it. Fat, skin and muscle convert precursors into more of it.
Why It Falls
Recent work out of Susan Davis's group at Monash puts the decline at roughly 50 percent between age 20 and age 60, with about a 25 percent drop across the twenties and thirties and another 25 percent from the forties into the late fifties. It is a slow, steady slide that starts long before anyone is talking about menopause.
Aging accounts for most of it, in both the ovary and the adrenal. But the ordinary things like short sleep, no resistance training, chronic stress, alcohol, and crash dieting will accelerate its decline.
What I See
There is not enough data to draw firm conclusions about what testosterone does for women beyond sexual desire. Not enough to say it works, but also not enough to say it does not.
Here is what I observe. Women I treat report that their mood lifts. Their libido returns. Their thinking clears — the brain fog is the one they name most often, and they name it unprompted. Their energy improves. They get stronger. And they tell me they enjoy sex again, which is not quite the same thing as desire returning and is often the change they care about most.
American women are paying out of pocket, month after month, for a hormone no insurer covers, that no company is allowed to market to them here, and that requires finding a physician willing to prescribe it off-label in the first place. It is not cheap and it is not easy. Yet, they come back for refills anyway, and they send their friends. Whatever is happening there, it is worth somebody's attention.
So, outside the sexual-desire indication, I am treating based on a hypothesis rather than on evidence. I think the evidence will move when somebody finally runs the trials. That might happen sooner than we think.
In July of last year the FDA convened an expert panel on menopausal hormone therapy. In November it stripped the boxed warnings off those products, with the commissioner saying tens of millions of women had been denied life-changing benefits because of medical dogma rooted in a distortion of risk. One month later, in December, the agency convened a panel on testosterone therapy for men, and that panel urged loosening labeling and access. Now, on September 17, it turns to testosterone in women with a workshop to examine the evidence and identify the knowledge gaps. This is the first time the agency has taken up this question directly.
What is on the agenda ought to interest you, because it is the argument in this article: how to measure testosterone in a woman, how to read the result, and what should count as a good enough reason to treat her. The agency's own notice names the gaps as sexual function, cognition, and musculoskeletal health.
The workshop is hybrid and free, and the comment docket is FDA-2026-N-5479 on regulations.gov, open through October 19. You do not need a medical degree to file a comment, and patient experience is a category the agency explicitly asked for. Ten minutes of your time carries further here than it will almost anywhere else.
What I Recommend
First, if you have the symptoms, get the number — and ask for it the right way, because this is where most women end up with a useless result. What you want is a calculated free testosterone by liquid chromatography–mass spectrometry. Draw it in the morning, and add estradiol, estrone, progesterone, FSH and DHT.
The number is not yet a diagnosis. There is no cutoff below which you have a disease and above which you do not, and no level yet identified predicts which women will feel better on treatment. What a properly measured level gives you is a starting point, a check on the other things that could explain how you feel, and — if you ever do treat — the only reliable way to know you have not been pushed somewhere no woman's body has ever been.
Second, be careful with "normal." That range rests on assays that were never designed to test testosterone in women.
Third, fix what is fixable. Seven to eight hours of sleep. Resistance training two or three times a week, with enough protein to support it. Alcohol modest.
Fourth, lower the chemical load. I have written a whole series on this, and if you read one thing, read the first part. The short version: filter your drinking water and keep it in glass, use glass and stainless instead of plastic, never microwave food in plastic, skip the paper receipt, choose fragrance-free, and dress in natural fibers. Plastics disrupt the endocrine system in women too, and the clearest signal is on the ovary itself: faster ovarian aging and earlier menopause.
Fifth, understand what treatment actually looks like in this country, because it is a mess. There is no FDA-approved testosterone product for women in the United States. Australia, the United Kingdom, New Zealand, and South Africa all have one. What that means in practice is that every woman treated here is treated off-label and will not be covered by insurance. Overdosing a woman with testosterone is very easy when using a male product. This is precisely how women end up at male levels by accident.
The vacuum is being filled. Something over two million testosterone prescriptions are now written for American women every year, a great many of them compounded. The demand behind it is real: sexual complaints climb steeply through the menopause transition, and midlife women have been dismissed for decades.
This year it got even harder, for a reason that has nothing to do with testosterone. Estrogen patches have been in short supply since the spring, as demand for menopausal hormone therapy has climbed faster than manufacturers have kept up. The FDA has said there is no shortage, but women standing at pharmacy counters have formed a different opinion.
If you cannot get a patch, or a cream is not working for you, there is another route. I place hormone pellets in my office — estradiol, and a small dose of testosterone — for women who would rather not manage a patch or a daily cream. How it is done matters more than the fact that it is offered. Testosterone starts as a cream, so we learn how you react to it before anything is implanted. The pellet dose is small. I move up only as far as your symptoms require and never past the physiologic range for a woman, and if side effects appear, the dose comes back down. That is a slower path than a ten-minute intake form, and it is the only version of this I am willing to offer.
The Bottom Line
The most abundant sex hormone in your body declines by half between your twenties and your sixties, and is almost never measured. If you are on hormone therapy and still feel flat, testosterone is the piece most likely to be missing from your panel.
I would like to hear from you. If you have asked about testosterone and been told women do not need it, leave a comment below and tell me how that conversation went.
To your good health,
The Longevity Doctor®
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