WOMEN'S HEALTH & HORMONES
Testosterone Blood Test for Women: What Is Measured, What Is Normal, and When a Low Level Matters
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Women produce testosterone too, at roughly a tenth of male levels, and it falls gradually with age. It is measured as total testosterone alongside SHBG, which together give a calculated free androgen index. There is no single agreed cut-off that defines “low” in women, so results are read with symptoms, not in isolation. In the UK it is tested most often when considering testosterone as part of menopause care for persistent low libido, and to check for the higher levels seen in PCOS.
Testosterone is usually thought of as a male hormone, but women make it throughout life, in the ovaries and adrenal glands. It contributes to libido, energy, mood and muscle, and like other hormones it drifts downward with age, with levels in the late forties roughly half what they were in the twenties.
Testing it in women is more nuanced than in men. Female levels are low to begin with, the assays need to be sensitive enough to measure them accurately, and there is genuine debate about what counts as too low. That does not make the test useless. It makes context everything.
This guide explains what is actually measured, what female ranges look like, when a low result is worth investigating, what the higher readings of PCOS mean, and how to make sure the test is done in a way that gives a usable answer.
1. Why women have testosterone at all
Testosterone is an androgen, and androgens are part of normal female physiology. In women it is produced by the ovaries and the adrenal glands, and some is converted from other hormones in the body's tissues. The amounts are small compared with men, but the role is real: it feeds into sexual desire, energy, mood, and the maintenance of muscle and bone.
Female testosterone peaks in early adulthood and then declines slowly and steadily with age, rather than dropping sharply at menopause the way oestrogen does. By the late forties, average levels are around half of their twenties peak. Removal of both ovaries causes a more sudden fall.
2. What is measured: total, SHBG, free androgen index
A meaningful testosterone test in women is rarely just one number. Three figures work together:
Total testosterone
The full amount in the blood, bound and unbound. On its own it can be misleading, because most testosterone is bound to a carrier protein and not available to tissues.
SHBG (sex hormone binding globulin)
The protein that carries testosterone. When SHBG is high, more testosterone is bound and less is active; when it is low, more is free. SHBG is affected by oestrogen, thyroid status, insulin and weight, so it shifts the picture in ways total testosterone cannot show.
Free androgen index
A calculation from total testosterone and SHBG that estimates how much testosterone is actually available. This is often the most useful figure in women, because it accounts for the binding protein rather than ignoring it.
If you already have a total testosterone and SHBG result, you can see the free fraction for yourself with the calculator below.
3. What a normal female range looks like
Female reference ranges for total testosterone are much lower than male ranges and vary between laboratories and assays. A common adult female range sits at roughly 0.3 to 1.7 nmol/L, but the exact figures on your report depend on the lab and the method used, so always read your result against the range printed alongside it.
The honest part is that there is no internationally agreed level that defines testosterone deficiency in women. Symptoms do not map neatly onto a single number, and many women with low-end readings feel perfectly well. That is why a result is a starting point for a conversation, not a verdict in itself.
What clinicians tend to watch for is a clearly low free androgen index in someone with relevant symptoms, or a clearly raised level pointing toward a different question entirely.
4. When a low level is worth investigating
The clearest reason to test in this direction is persistent low sexual desire that is causing distress and has not improved on oestrogen replacement. The British Menopause Society supports considering testosterone in this situation, off-licence, with a baseline level taken first.
The reason for the baseline is twofold: to confirm the starting level is not already high, and to give a number to compare against once any treatment begins. If testosterone is started, a follow-up level keeps the dose within the female physiological range rather than above it. The practical side of that monitoring is covered in the HRT blood test guide.
It is worth being realistic: symptoms like fatigue and low mood have many causes, and a low-normal testosterone is rarely the whole story. Thyroid, iron, vitamin D, sleep and stress all deserve a look before testosterone is assumed to be the answer.
5. High testosterone and PCOS
In women, a raised testosterone is often the more clinically useful finding, and the most common reason for it is polycystic ovary syndrome (PCOS). Higher androgen levels can show up as irregular periods, acne, and unwanted hair growth, and testosterone is one of the markers used as part of assessing PCOS.
A clearly high testosterone always belongs with a clinician, who can place it in the full picture and decide what else to check. The PCOS blood test guide walks through the wider panel used to assess it.
6. Getting an accurate result
Because female testosterone is low, how and when the blood is taken matters more than people expect.
- Test in the morning, when testosterone is at its steadiest and highest point of the day.
- Always have SHBG measured alongside total testosterone, so a free androgen index can be calculated rather than guessed.
- If you have regular cycles, the first half of the cycle is a reasonable window; if cycles are absent or irregular, timing is less critical.
- Note any hormonal contraception or HRT you use, since both change SHBG and shift how the result reads.
The right window depends on your situation, and the hormone timing guide covers it for each hormone.
7. NHS and private testing
The NHS will usually test testosterone in women where there is a clear clinical reason, most often when PCOS or another cause of raised androgens is suspected. Testing specifically to explore low testosterone and libido is more variable, and access can depend on the clinician and the service.
Private testing can give you a clear baseline of total testosterone and SHBG, ideally as part of a broader hormone panel that also covers oestradiol, FSH and thyroid, so the result is read in context rather than alone. Whatever the numbers, decisions about treatment are made with a qualified clinician.
8. Frequently asked questions
Do women have testosterone?
Yes. Women produce testosterone in the ovaries and adrenal glands, at roughly a tenth of male levels. It contributes to libido, energy, mood, muscle and bone, and declines gradually with age.
What is a normal testosterone level for a woman?
Female ranges are much lower than male ones and vary by laboratory, with a common adult range around 0.3 to 1.7 nmol/L for total testosterone. There is no single agreed level that defines deficiency, so results are read alongside SHBG and symptoms.
What does the free androgen index tell me?
It estimates how much testosterone is actually available to tissues, calculated from total testosterone and SHBG. It is often more useful in women than total testosterone alone, because most testosterone is bound to SHBG and not active.
Can low testosterone cause low libido in women?
It can contribute, and the British Menopause Society supports considering testosterone, off-licence, for persistent distressing low desire that has not improved on oestrogen. A baseline level is taken first. Low libido has many causes, so testosterone is one part of a wider assessment.
What does high testosterone in a woman mean?
The most common reason is polycystic ovary syndrome (PCOS), which can show up as irregular periods, acne and unwanted hair growth. A clearly raised level should be assessed by a clinician as part of a fuller picture.
When should a woman have a testosterone blood test?
Test in the morning, with SHBG measured alongside. If you have regular cycles, the first half of the cycle is a reasonable window. Note any contraception or HRT, since both change SHBG and how the result reads.
READY TO TEST?
Read testosterone in context, not on its own.
A Helvy Hormone Balance panel checks testosterone, SHBG, oestradiol, FSH, LH, progesterone, DHEA-S and thyroid markers in one home finger-prick kit. Results in 5 working days, analysed at UKAS-accredited UK laboratories, with qualified clinician review.
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