SHBG test: normal range and what high or low SHBG means

An SHBG test measures sex hormone-binding globulin, the protein that carries testosterone and estradiol in the blood. Hormone held by SHBG cannot act on tissues, so the SHBG level decides how much of a person's testosterone is actually available. That is why SHBG is almost always read alongside total testosterone.

What SHBG is

SHBG is made mostly in the liver. It binds sex hormones, mainly testosterone and estradiol, and so controls how much of them is free to work in the body. The liver's output of SHBG changes through life and responds to metabolic and hormonal signals, and genes account for part of the difference between people.

A total testosterone result counts bound and free hormone together. With SHBG alongside it, the free share can be calculated. When SHBG is high, more testosterone is held back and less is free. When SHBG is low, more is free. Two people with the same total testosterone can therefore have quite different amounts of usable hormone.

Normal range

SHBG is reported in nmol/L. The ranges are wide, differ between women and men, change with age and vary between laboratories, as these two NHS laboratories show.

Ranges vary by laboratory, method, age and sex, and the range on your own report is the one to read against. Children normally have much higher SHBG, which falls through puberty.

What a high SHBG usually points to

A high SHBG means less of the total testosterone is likely to be free. Common reasons include:

• ageing in men: in one large US study, SHBG was about 1.6% higher for each year of age
• an overactive thyroid
• liver disease
• oestrogen-containing medicines, such as the combined pill or menopause hormone therapy
• some eating disorders
• some anticonvulsant medicines, and HIV
• smoking, which went with SHBG about 6 nmol/L higher in European men aged 40 to 79

Doctors usually look next at total testosterone and calculated free testosterone, at thyroid tests such as TSH, and at liver tests. In a man with symptoms of low testosterone and a total within range, a high SHBG is one reason the free figure can still be low, and the Endocrine Society recommends a free testosterone result whenever SHBG is likely to be altered.

What a low SHBG usually points to

A low SHBG means more of the total is likely to be free. It is common with:

• excess weight
• insulin resistance and type 2 diabetes
• an underactive thyroid
• polycystic ovary syndrome (PCOS) in women
• glucocorticoids, progestins and anabolic steroids
• conditions such as Cushing's syndrome, acromegaly and nephrotic syndrome

The link with blood sugar is strong. In a US study of postmenopausal women, repeated in men, people in the top quarter of SHBG had about one tenth the odds of developing type 2 diabetes of those in the bottom quarter. A low SHBG is a reason to look at HbA1c, fasting glucose and fasting insulin. In women, a low SHBG with a higher free androgen index is part of the picture doctors read when PCOS is in question.

What moves SHBG

• Hormones and medicines. The combined pill and other oestrogen-containing medicines raise SHBG; anabolic steroids, glucocorticoids and progestins lower it.
• Thyroid function. SHBG tends to rise when the thyroid is overactive and fall when it is underactive.
• Weight and insulin. SHBG falls as weight and insulin resistance rise.
• Pregnancy. Estradiol occupies part of SHBG's binding sites, so free testosterone calculated from SHBG reads lower than the true value in pregnancy.
• Time of day. SHBG changes much less across the day than testosterone does.
• Laboratory factors. SHBG is measured by immunoassay, and high-dose biotin supplements can push some immunoassays falsely low or high, depending on their design.

Preparing for the test

SHBG itself needs no special preparation. It is usually taken with testosterone, which is measured on a morning sample while fasting, so follow the instructions for that. Tell the person taking the sample about hormone-containing medicines and supplements, including biotin, but do not stop anything without your doctor's advice.

How Clare's panel handles it

In Clare's panel, SHBG is measured by the lab, alongside total testosterone and albumin. Clare uses the three to calculate free testosterone with the Vermeulen equation, and divides total testosterone by SHBG, multiplied by 100, to give the free androgen index.

Why it matters in the UAE

The International Diabetes Federation estimated that 20.7% of adults in the UAE had diabetes in 2024. Because a low SHBG tracks insulin resistance and has predicted type 2 diabetes in women and men, SHBG is worth reading next to the blood sugar markers rather than on its own.

Price

None of the public price lists we read sold SHBG as a single test; it comes inside a testosterone or male hormone test. When we read public prices on 11 October 2026, a testosterone test cost from 65 to 1,599 at 9 UAE providers. The cheapest options measure total testosterone alone, without SHBG. The two packages that named SHBG cost 449 and 1,599, and the dearer one includes a specialist consultation. VAT is rarely stated, some prices were offers, and home collection can add a fee.

Related tests

SHBG is read with total testosterone, part of the testosterone test, and it feeds calculated free testosterone and the free androgen index. Because thyroid function and blood sugar both move SHBG, the thyroid test and HbA1c are useful alongside. Our articles on how we read a thyroid panel and reading HbA1c, glucose and insulin together cover those.

Why the number means more over time

SHBG changes slowly with age, weight, thyroid function and medicines, so a change between tests often says more than a single value. A rise after starting the combined pill, or a fall as weight and insulin resistance increase, fits the known pattern. A shift with no clear reason is worth raising with a doctor, with both results in front of you. SHBG is usually rechecked whenever testosterone is, ideally at the same laboratory. Clare is opening with a waitlist at clare.health.