What is total testosterone?
Testosterone is the main male sex hormone, but everyone has it. In men the testes make it, driven by LH from the pituitary; in women a tenth to a twentieth of that amount comes from the ovaries and the adrenal glands. It builds muscle and bone, drives desire, energy and drive, keeps the production of red blood cells up and, in men, helps decide sperm production. Most testosterone in your blood travels bound to protein: tightly to SHBG and loosely to albumin. Only the free part, a few percent, can enter the cell and do its work. Total testosterone adds everything up, bound and free. That is the standard measurement and usually enough, but with a high or low SHBG the active part shifts without the total moving, and then SHBG belongs beside it. Your report shows testosterone in nmol/L, with one range for men and one for women that do not meet: where the labs overlap it runs from 9.0 to 27.3 nmol/L in a man of 20 to 50 years and from 0.3 to 1.7 nmol/L in a woman of the same age. The range falls slightly with age, and it depends on the time of day: testosterone is highest in the morning and a quarter lower in the afternoon, so have blood drawn before ten.
Why is total testosterone relevant?
For men testosterone is one of the most honest lifestyle values on the report. It falls with belly fat, because fat tissue converts testosterone into oestradiol and insulin resistance suppresses production. It falls with lack of sleep, because most testosterone is made during sleep; a week of short nights already makes a noticeable difference. It falls with lasting stress, with plenty of alcohol, with overtraining and eating too little, and with sleep apnoea. And it falls slowly with age, about one percent a year from around thirty, though in fit men much less than assumed. That makes a low testosterone in a man of forty usually not a matter of a hormone that has run out, but of a body that does not make it because the conditions are not right. Little desire, little energy, less muscle and more belly are the complaints, and they reinforce each other: less testosterone gives more belly fat, and more belly fat gives less testosterone. Anyone who breaks that circle, with losing weight, strength training and sleep, usually sees the number come back. In women testosterone plays a different role: it carries desire, energy and muscle, and the most common problem is too much rather than too little. A raised testosterone in a woman usually belongs to PCOS, with an irregular cycle, excess hair growth and acne, and there too insulin resistance sits underneath. Testosterone as a medicine is there for men with a persistently low testosterone on two mornings and symptoms, once LH has shown where it lies. It is not a remedy for tiredness or getting older: it shuts down production of your own, reduces fertility and thickens the blood, and in most men with a moderately low number lifestyle works better and without that price.
Total testosterone reference ranges
What counts beside the number:
- The time: before ten in the morning, after a normal night, and a low value repeated on a second morning
- SHBG, which shows how much of the total is free; with excess weight or with age the total tells only half the story
- LH, which with a low value shows whether it is the testes or the signal from the brain
- Your waist, sleep, alcohol, training load and stress, the levers the number responds to
- Medicines: opioids, prednisone, anabolic steroids, and in women the pill
- In women: the cycle, excess hair growth and acne, which point at PCOS
The bands above are where the labs overlap; the range on your own report may be wider, and there is no national normal value. The bands for men and women do not meet. All bands apply to a morning value; in the afternoon testosterone sits a quarter lower. With a high or low SHBG the total tells only half the story, and then free testosterone belongs beside it.
What Dutch labs actually use
The four labs publish two bands for testosterone that do not meet, one for men and one for women, with a gap in between. Where they overlap, the female band from 20 to 50 yrs stops at 1.7 nmol/L and the male band of the same age only starts at 9.0 nmol/L. For men the difference sits mainly in the ceiling. Unilabs runs its band up to 37.3 nmol/L and Clinical Diagnostics stops as low as 27.3, with Certe and Star-shl in between at 32.4 and 29.0. The floors sit closer together: 9.0 at Unilabs, 8.8 at Certe, 8.6 at Star-shl and 6.1 at Clinical Diagnostics. The second line is age, and the labs fill it in differently. Unilabs lowers the male band in two steps, around the fiftieth year and once more above eighty; Star-shl lowers it once, at 50; Certe and Clinical Diagnostics hold one band. In the shared band the male floor therefore drops from 9.0 down to 8.8 nmol/L, less than the labs differ from each other: their floors for a man from 20 to 50 yrs run from 6.1 to 9.0 nmol/L. Where the four labs overlap, a man from 20 to 50 yrs is left with 9.0 to 27.3 nmol/L and from 50 yrs with 8.8 to 25.7 nmol/L. A woman is left with 0.3 to 1.7 nmol/L from 20 to 50 yrs and with 0.17 to 1.4 nmol/L from 50 yrs.
0.3 – 1.7nmol/L
Between 0 and 0.3 and between 1.7 and 2.6 it depends on the lab, because each sets its limits on its own method and population. Above 2.6 every lab calls it abnormal.
every lab calls 0.3 – 1.7 nmol/L normal. Between 0 and 0.3 and between 1.7 and 2.6 it depends on the lab.
Every age, per lab
| Laboratory | Group | Reference range |
|---|---|---|
| Unilabs(Saltro, Medlon, SHO, Atalmedial)2026 | Men 20 to 50 yrs | 9.0–37.3 nmol/L |
| Men 50 to 80 yrs | 7.6–37.1 nmol/L | |
| Men from 80 yrs | 5.4–36.8 nmol/L | |
| Women 20 to 50 yrs | 0.2–2.1 nmol/L | |
| Women from 50 yrs | 0.1–1.8 nmol/L | |
| Star-shl2026 | Men 18 to 49 yrs | 8.6–29.0 nmol/L |
| Men from 50 yrs | 6.7–25.7 nmol/L | |
| Women 18 to 49 yrs | 0.3–1.7 nmol/L | |
| Women from 50 yrs | 0.1–1.4 nmol/L | |
| Certe2026 | Women 16 to 20 yrs | 0.1–1.7 nmol/L |
| Men 16 to 20 yrs | 4–24 nmol/L | |
| Women (all ages) | 0.17–1.81 nmol/L | |
| Men (all ages) | 8.8–32.4 nmol/L | |
| Clinical Diagnostics2026 | Men | 6.1–27.3 nmol/L |
| Women | 0–2.6 nmol/L |
Each band as the lab publishes it, retrieved in 2026, unless marked otherwise.
Total testosterone high or low: what it means
A low testosterone in a man is, in order of how often it occurs: drawn too late in the day or after a short night, belly fat and insulin resistance, lack of sleep or sleep apnoea, lasting stress, plenty of alcohol, overtraining or eating too little, and age. Then medicines: opioids, prednisone and anabolic steroids, which shut down production of your own. Rarely it is the testes themselves or the pituitary, and LH keeps those two apart: a high LH with a low testosterone is the testes, a low or normal LH is the signal from the brain, and that is almost always the reversible part. A high testosterone is rarely a problem in men and usually testosterone from outside, from a gel, injection or anabolic steroids. In women a raised value is usually PCOS; a strongly raised value, a multiple of the range, is rare and calls for investigation of ovaries and adrenal glands. A low testosterone in women is rarely measured and rarely treated: the pill lowers it via SHBG, and that is then the intention. The levers are strong and concrete in men. Losing weight around the middle is the biggest, and ten percent weight loss already lifts testosterone noticeably in a man with excess weight. Strength training, because muscle demands and makes testosterone, and heavy exercises with large muscle groups work best. Seven to eight hours of sleep, and having sleep apnoea treated if it is there. Less alcohol, and enough food for what you train: an energy deficit shuts the signal down. In women with PCOS, losing weight and less sugar and fast carbohydrates work the same way, through the insulin resistance underneath. Never read testosterone on its own. SHBG shows how much of the total is free; in a heavy or ageing body the total tells only half the story. LH shows where a low value comes from. In men oestradiol belongs beside it when there is belly fat, in women the cycle day. And repeat a low value on a second morning before drawing anything from it.
What lowers it
Usually the moment of the draw and the conditions you live in; rarely the testes themselves.
| Cause | How often |
|---|---|
| The time of the drawTestosterone is highest in the morning and a quarter lower in the afternoon; after a short night it also sits lower. Draw before ten and repeat a low value on a second morning | Often |
| Excess weight and insulin resistanceBelly fat converts testosterone into oestradiol and insulin resistance suppresses production and SHBG; the largest reversible cause in men | Often |
| Lack of sleep and sleep apnoeaMost testosterone is made during sleep; a week of short nights already makes a noticeable difference, and sleep apnoea suppresses it persistently | Often |
| AgeAbout one percent a year from around thirty, much less in fit men; that is why the labs let the range fall slightly | Often |
| Eating too little, training too much or lasting stressAn energy deficit and cortisol turn the signal from the brain down low; LH and testosterone drop together | Sometimes |
| Medicines that shut production downOpioids, prednisone and anabolic steroids suppress LH and with it production of your own; after steroids recovery takes months | Sometimes |
| Testes making lessAfter an infection, from a congenital cause or after chemotherapy; LH then sits high instead, and that is the difference from all the causes above | Rare |
What raises it
In men usually from outside, in women usually PCOS.
| Cause | How often |
|---|---|
| Testosterone from outsideA gel, injection or anabolic steroids lift the total and shut down production of your own; LH and FSH then sit low | Sometimes |
| Polycystic ovary syndrome (PCOS)In women the most common reason for a raised testosterone, with an irregular cycle, excess hair growth and acne; insulin resistance and belly fat sit underneath | Sometimes |
| A tumour of the ovary or adrenal glandRare; the value then sits a multiple above the range and the symptoms come on quickly | Rare |
How does a total testosterone blood test work?
- Referral
- Not needed. You can have testosterone measured without going through your GP.
- When to draw
- Before ten in the morning, after a normal night and not after a heavy training session or an evening with plenty of alcohol. In the afternoon the value sits a quarter lower.
- Fasting
- Preferably yes: a meal lowers testosterone temporarily. So have blood drawn before breakfast.
- The result
- A single number in nmol/L, with one range for men and one for women. Usually available within a few days.
- Repeating
- A low value always on a second morning, because testosterone fluctuates from day to day. After losing weight, strength training or sleeping better you see the difference after three to six months.
- Where to draw
- You can draw at 350+ locations near you, no referral needed. See the locations
Frequently asked questions
All the testosterone in your blood together: the part bound to SHBG and albumin and the free part that can do its work in the cells. It is the hormone that carries muscle, bone, desire and energy, in men in large amounts and in women in small ones. With a high or low SHBG the active part shifts without the total moving, and then SHBG belongs beside it.
Related biomarkers
Read on
Sources
- 1.Unilabs, test catalogue (Dutch): total testosterone. 2026. bepalingenklapper.nl
- 2.Star-shl, test catalogue (Dutch): total testosterone. 2026. star-shl.nl
- 3.Certe, test catalogue (Dutch): total testosterone. 2026. bepalingenwijzer.certe.nl
- 4.Clinical Diagnostics, lab guide (Dutch): total testosterone. 2026. clinicaldiagnostics.nl
Educational information only, not medical advice. Consult a healthcare professional for clinical decisions.
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