What is SHBG?
SHBG is a protein your liver makes and that binds testosterone and oestradiol in your blood. As long as a hormone is attached to it, it is in transit and not available; only the free part can enter the cell. SHBG is therefore the regulator of how much of your sex hormones is active: at the same total testosterone a high SHBG leaves little free and a low SHBG plenty. How much SHBG your liver makes depends on what is happening in your body. Insulin suppresses production, which is why SHBG falls with belly fat, insulin resistance and a fatty liver, often years before blood sugar moves. Oestrogen and thyroid hormone drive production, which is why SHBG rises on the pill, in pregnancy and with an overactive thyroid. It also rises with age, especially in men, and with eating too little or a low body weight. Your report shows SHBG in nmol/L, with one range for men and one for women: women sit about twice as high, because oestrogen drives production. Normal is 18 to 54 nmol/L in a man of 19 to 49 years and 32 to 128 nmol/L in a woman of 19 to 47 years, where the labs overlap.
Why is SHBG relevant?
SHBG is worth knowing for two reasons, and the first has nothing to do with hormones. A low SHBG is one of the earliest signs of insulin resistance: the liver makes less SHBG as soon as it sees too much insulin and too much fat, and that happens long before fasting glucose or HbA1c moves. A low SHBG in a man with belly fat or a woman with PCOS is therefore not a hormone problem but a metabolic signal, and one of the better predictors of type 2 diabetes to be found on an ordinary report. The second reason is reading testosterone. Without SHBG a total testosterone can only be half read. A man with excess weight often has a low total testosterone and a low SHBG, so the free part is better than it looks; an older man or a man with an overactive thyroid has a normal total with a high SHBG, so the free part is worse than it looks. In women with PCOS a low SHBG is precisely the reason a normal total testosterone still yields too much active androgen, with excess hair growth and acne as the result. That is why SHBG belongs with every testosterone test, and why they move in opposite directions with weight loss: SHBG rises and free testosterone is thereby distributed more healthily.
SHBG reference ranges
What counts beside the number:
- Total testosterone from the same tube, and the free part that follows from the two
- Your waist, triglycerides, fasting glucose and liver values, which with a low SHBG tell the same story
- The pill or hormone therapy, which raise SHBG strongly
- Your thyroid: underactive lowers, overactive raises
- Your age, because SHBG rises with the years, especially in men
- Whether you eat enough for what you train
The bands above are where the labs overlap; the range on your own report may be wider, and there is no national normal value. SHBG belongs read beside a total testosterone from the same tube. For anyone who wants to stay healthy the bottom of the range says the most: an SHBG at the bottom belongs to belly fat and insulin resistance.
What Dutch labs actually use
Three labs publish a reference value for SHBG. Star-shl does not carry the determination in its test index, so this page sets three tables side by side instead of four. The biggest difference is not between the labs but between men and women. Where the three overlap, a man from 19 to 49 yrs is left with 18 to 54 nmol/L and a woman from 19 to 47 yrs with 32 to 128 nmol/L. The women's band starts almost twice as high and runs more than twice as far. The labs also cut that women's band at different ages, Certe at 49 yrs and Clinical Diagnostics at 47. From that age a woman is left with 27 to 125.2 nmol/L and a man with 21 to 71 nmol/L, because Certe lifts its male band after the forty-ninth year while the ceiling of 71 at Unilabs stays where it is.
32 – 128nmol/L
Between 18.2 and 32 and between 128 and 155 it depends on the lab, because each sets its limits on its own method and population. Above 155 every lab calls it abnormal.
every lab calls 32 – 128 nmol/L normal. Between 18.2 and 32 and between 128 and 155 it depends on the lab.
Every age, per lab
| Laboratory | Group | Reference range |
|---|---|---|
| Unilabs(Saltro, Medlon, SHO, Atalmedial)2026 | Women from 17 yrs | 20–155 nmol/L |
| Men from 19 yrs | 14–71 nmol/L | |
| Men 15 to 19 yrs | 10–50 nmol/L | |
| Certe2026 | Women up to 19 yrs | 20–100 nmol/L |
| Women 19 to 49 yrs | 32–128 nmol/L | |
| Women from 49 yrs | 27–128 nmol/L | |
| Men 12 to 19 yrs | 12–30 nmol/L | |
| Men 19 to 49 yrs | 18–54 nmol/L | |
| Men from 49 yrs | 21–77 nmol/L | |
| Clinical Diagnostics2026 | Men | 13.3–89.5 nmol/L |
| Women 20 to 46 yrs | 18.2–135.5 nmol/L | |
| Women from 47 yrs (post-menopausal) | 16.8–125.2 nmol/L |
Each band as the lab publishes it, retrieved in 2026, unless marked otherwise.
SHBG high or low: what it means
A low SHBG means, first of all, too much insulin: belly fat, insulin resistance, a fatty liver, and in women PCOS. Beyond that an underactive thyroid, prednisone, growth hormone and anabolic steroids, and in women some progestogens. The result is more free testosterone at the same total: in men that masks a low total, in women it amplifies the androgenic complaints. A high SHBG usually means oestrogen or thyroid hormone: the pill, hormone therapy, pregnancy, an overactive thyroid. It also rises with age, especially in men over fifty, with eating too little and a low body weight, and with serious liver disease. The result is less free testosterone at the same total: a normal total with complaints of too little testosterone in an older man is often a high SHBG. The lever with a low SHBG is that of insulin resistance, and it works: losing weight around the middle, less sugar, soft drinks and fast carbohydrates, and daily movement let SHBG rise within months. It is one of the few hormone values you can improve under your own steam, and it is also the proof that the lifestyle change is landing. A high SHBG from the pill or age is not something to lower; there free testosterone is the value to look at. Always read SHBG beside total testosterone, and have free testosterone or the FAI calculated. With a low SHBG a look at triglycerides, fasting glucose and the liver values belongs too, because they tell the same story from the other side.
What lowers it
Almost always too much insulin, and beyond that whatever suppresses production in the liver.
| Cause | How often |
|---|---|
| Excess weight and insulin resistanceInsulin suppresses the production of SHBG in the liver; belly fat and a fatty liver are the most common cause, years before blood sugar moves | Often |
| Polycystic ovary syndrome (PCOS)Insulin resistance suppresses SHBG, so that at a normal total testosterone more androgen is active; excess hair growth and acne are the result | Sometimes |
| Underactive thyroidThyroid hormone drives production, so with an underactive thyroid SHBG falls; TSH shows it | Sometimes |
| Medicines that suppress productionPrednisone, anabolic steroids, growth hormone and in women some progestogens lower SHBG | Sometimes |
What raises it
Oestrogen, thyroid hormone, age and eating too little.
| Cause | How often |
|---|---|
| Hormonal contraceptionThe oestrogen in the pill drives production in the liver strongly; SHBG can double and free testosterone falls with it | Often |
| AgeSHBG rises with the years, especially in men over fifty; a normal total testosterone then leaves less free | Often |
| Overactive thyroidThyroid hormone drives production; a high SHBG is sometimes the first sign of an overactive thyroid | Sometimes |
| Eating too little or a low body weightWith little insulin and little fat the liver makes more SHBG; in athletes with an energy deficit it rises along with the cycle switching off | Sometimes |
| Serious liver diseaseIn cirrhosis SHBG rises, while most other liver proteins fall | Rare |
How does a SHBG blood test work?
- Referral
- Not needed. You can have SHBG measured without going through your GP; request it together with total testosterone.
- Fasting
- Not needed for SHBG itself, but useful because the testosterone from the same tube is drawn in the morning and preferably fasting.
- The draw
- One tube of blood from a vein in your arm, with total testosterone from the same tube.
- The result
- A single number in nmol/L, with one range for men and one for women. Usually available within a few days.
- Repeating
- With a low SHBG, again after three to six months of losing weight and less sugar; the rise is the proof that insulin resistance is easing.
- Where to draw
- You can draw at 250+ locations near you, no referral needed. See the locations
Frequently asked questions
What is SHBG?
Sex hormone binding globulin is a protein your liver makes and that holds testosterone and oestradiol in your blood. As long as a hormone is attached to it, it is not available; only the free part can enter the cell. How much SHBG you make depends on insulin, oestrogen, thyroid hormone, weight and age, which makes it both a hormone value and a metabolic value.
What is a normal SHBG level?
In a man of 19 to 49 years 18 to 54 nmol/L and from 49 years 21 to 71 nmol/L. In a woman of 19 to 47 years 32 to 128 nmol/L and from 49 years 27 to 125.2 nmol/L; women sit about twice as high because oestrogen drives production. For anyone who wants to stay healthy the bottom is the most interesting: a value at the bottom of the range belongs to belly fat and insulin resistance.
What does a low SHBG mean?
Almost always too much insulin: belly fat, insulin resistance or a fatty liver, years before blood sugar moves. In women it belongs to PCOS, where the low SHBG lets more androgen act and amplifies excess hair growth and acne. An underactive thyroid, prednisone and anabolic steroids lower it too. The result is more free testosterone at the same total, which in men masks a low total.
What does a high SHBG mean?
Usually oestrogen or thyroid hormone: the pill, hormone therapy, pregnancy or an overactive thyroid. It also rises with age, especially in men over fifty, and with eating too little or a low weight. The result is less free testosterone at the same total: a normal total with complaints of too little testosterone in an older man is often a high SHBG. In itself a high SHBG is not something to lower.
How do I raise a low SHBG?
By addressing the insulin resistance behind it: losing weight around the middle, less sugar, soft drinks and fast carbohydrates, and daily movement. SHBG then rises within three to six months, and that rise is the proof that the lifestyle change is landing. Free testosterone is thereby distributed more healthily, and in women with PCOS the androgenic complaints ease.
Why does SHBG belong with a testosterone test?
Because without SHBG total testosterone can only be half read. A man with excess weight often has a low total and a low SHBG, so the free part is better than it looks; an older man has a normal total with a high SHBG, so the free part is worse than it looks. From total testosterone and SHBG, free testosterone or the FAI is calculated, and that is the number that goes with the complaints.
Is a low SHBG a predictor of diabetes?
Yes, and one of the better ones on an ordinary report. The liver makes less SHBG as soon as it sees too much insulin and fat, and that happens long before fasting glucose or HbA1c moves. A low SHBG beside high triglycerides and a large waist is the pattern that precedes type 2 diabetes, and exactly the pattern that lifestyle can reverse.
Do I have to fast for an SHBG test?
Not for SHBG itself, but it is measured from the same tube as testosterone, and that you draw in the morning and preferably fasting. So request the two together, before ten and before breakfast.
Which tests include SHBG?
SHBG is in the Hormones men test (€129, also as an add-on for €109).
Related biomarkers
Read on
Sources
- 1.Unilabs, test catalogue (Dutch): SHBG. 2026. bepalingenklapper.nl
- 2.Certe, test catalogue (Dutch): SHBG. 2026. bepalingenwijzer.certe.nl
- 3.Clinical Diagnostics, lab guide (Dutch): SHBG. 2026. clinicaldiagnostics.nl
- 4.NHG guideline on amenorrhoea (M58), Dutch College of General Practitioners. 2018. richtlijnen.nhg.org
Educational information only, not medical advice. Consult a healthcare professional for clinical decisions.
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