Sex Hormone Binding Globulin (SHBG)
SHBG is a protein that binds and carries sex hormones in the blood. Low SHBG increases free testosterone and is associated with PCOS, insulin resistance, and metabolic syndrome.
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What the Sex Hormone Binding Globulin (SHBG) test tells you
Sex hormone binding globulin, usually shortened to SHBG, is a carrier protein made by the liver. Most of the testosterone and oestradiol circulating in the blood is not floating free — it is held by SHBG, which binds it tightly, and by albumin, which holds it loosely. Only the small unbound portion, together with the part loosely attached to albumin, can readily leave the bloodstream and act on tissues. SHBG therefore does not produce any hormone of its own; what it does is decide how much of the hormone already present is actually available to be used.
That role is why SHBG is measured. Two people can have an identical total testosterone and yet be in quite different situations, because one has a high SHBG holding most of it out of circulation and the other has a low SHBG leaving more of it active. This is the single most common reason a total testosterone result and a person's symptoms fail to agree, and it is why SHBG is requested alongside testosterone rather than on its own. From the two together, a free testosterone can be calculated and the picture usually resolves.
SHBG also carries information in its own right, because the things that move it are informative. It falls with excess body weight, insulin resistance, an underactive thyroid, and exposure to androgens or anabolic steroids, so a low SHBG often appears in metabolic syndrome and in polycystic ovary syndrome — where the low level raises the active fraction of testosterone and contributes to the symptoms. It rises with an overactive thyroid, with oral oestrogen including some contraceptives, in pregnancy, with liver disease and with age. Read this way it becomes a useful cross-check on whether a hormone result makes sense in the context of the rest of the person.
Essential for interpreting testosterone results, evaluating PCOS in women, assessing hypogonadism in men, and understanding metabolic syndrome risk.
SHBG is the reason a total testosterone can look normal while symptoms persist, so measuring the two together often explains an apparent contradiction.
The unbound, active fraction is usually derived from total testosterone together with SHBG and albumin rather than measured directly.
A low SHBG raises the proportion of testosterone that is active, which is a common contributor to symptoms in polycystic ovary syndrome.
SHBG falls with insulin resistance and excess weight, so a low result can prompt a wider look at metabolic risk.
Reasons your doctor may request the Sex Hormone Binding Globulin (SHBG) test
Your doctor may order this test for any of the reasons below. Some are routine checks, others follow specific symptoms or an earlier result.
Low testosterone, excess hair & acne
Investigating symptoms of low testosterone in a man, particularly where the total result is borderline.
Assessment of polycystic ovary syndrome, excess hair growth or acne in a woman.
When hormone results do not fit
Any situation where SHBG is expected to be unusual — obesity, thyroid disease, liver disease or oestrogen therapy.
Investigating persistent symptoms when previous hormone results have not fitted the clinical picture.
Free testosterone & replacement therapy
Calculating free testosterone as part of a fuller androgen assessment.
Monitoring during testosterone replacement, where SHBG shapes how much of the dose is active.
No fasting window — pick any slot that suits you, online or on WhatsApp.
A DHA-licensed nurse collects your sample at home or in the office — free home collection.
A physician-reviewed, easy-to-read report lands securely by WhatsApp and email.
SHBG binds sex hormones and affects how much is active.
Ranges are a guide — your physician interprets your result alongside your symptoms and history.
What a higher result can point to
- An overactive thyroid, which raises SHBG production by the liver.
- Oral oestrogen, including some combined contraceptives and menopausal hormone therapy, and the raised oestrogen of pregnancy.
- Liver disease, particularly cirrhosis, which alters how the liver makes and handles carrier proteins.
- Very low body weight, disordered eating or prolonged undernutrition.
- Increasing age in men, which is one reason total testosterone can hold up while the active fraction falls.
- Some medications, including certain anticonvulsants.
What a lower result can point to
- Excess body weight and insulin resistance, the commonest reasons for a low SHBG.
- Type 2 diabetes and metabolic syndrome, in which a low SHBG is a frequent accompanying finding.
- Polycystic ovary syndrome, where the low level increases the active fraction of testosterone.
- An underactive thyroid, which reduces liver production of the protein.
- Testosterone therapy, anabolic steroid use or other androgen exposure.
- Glucocorticoid treatment, and conditions in which protein is lost through the kidneys.
These are possibilities, not diagnoses. A single value outside the reference range is interpreted alongside your symptoms, history and other tests — your doctor decides what it means for you.
What this test cannot tell you
- SHBG is not a diagnosis on its own; it is interpreted as part of a testosterone or oestrogen assessment and has little meaning in isolation.
- Calculated free testosterone depends on assumptions built into the formula and on the albumin value used, so results from different calculations are not interchangeable.
- Oestrogen therapy, thyroid disease and liver disease all move SHBG substantially, and these need to be known before the result can be judged.
- A single measurement reflects current metabolic and hormonal conditions, which can change as weight, thyroid status or medication changes.
Risks of the blood draw
- Mild bruising or brief soreness where the needle went in.
- Occasional lightheadedness, which settles after a few minutes of rest.
- Bleeding or infection at the site, which is rare with sterile single-use equipment.
- 1SHBG is a carrier protein, not a hormone; it decides how much of your sex hormone is available rather than how much exists.
- 2It is the usual explanation when total testosterone and free testosterone tell different stories.
- 3A low SHBG is closely linked to excess weight and insulin resistance; a high one to thyroid overactivity, oestrogen and liver disease.
- 4Free testosterone is normally calculated from total testosterone, SHBG and albumin together.
- 5It should be requested alongside a testosterone measurement, not on its own.
Frequently Asked Questions
Everything you need to know about the Sex Hormone Binding Globulin (SHBG) test. Can't find what you're looking for?
Talk to our team→Because the carrier decides how much of the hormone can act. Two people with the same total testosterone can differ considerably in how much is available to their tissues, depending entirely on their SHBG. Measuring it turns an ambiguous total result into an interpretable one.
The most frequent explanations are excess body weight and insulin resistance, which both reduce how much of the protein the liver makes. An underactive thyroid and any androgen exposure, including testosterone therapy, do the same. Your doctor will look at the result in the context of your weight, thyroid tests and medications.
Yes, noticeably. Oestrogen taken by mouth increases SHBG production by the liver, which raises the total testosterone while lowering the fraction that is active. This is worth knowing before testosterone results from someone using combined contraception are interpreted.
In most laboratories it is calculated from total testosterone, SHBG and albumin. The calculation is reliable enough for everyday use but rests on assumptions, so an unexpected result may prompt your doctor to repeat the tests or request a directly measured free testosterone.
SHBG is a protein that binds and carries sex hormones in the blood. Low SHBG increases free testosterone and is associated with PCOS, insulin resistance, and metabolic syndrome.
Essential for interpreting testosterone results, evaluating PCOS in women, assessing hypogonadism in men, and understanding metabolic syndrome risk.
No, fasting is not required for the Hormone Transport Protein test, so you can eat and drink normally beforehand.
The Hormone Transport Protein test uses a blood sample, collected quickly by our DHA-licensed phlebotomist with minimal discomfort.
Results for the Hormone Transport Protein test are typically ready within 1 day. You will receive a secure digital report, and your Smart Report highlights anything outside the normal range.
The Hormone Transport Protein test is AED 319, which includes free home sample collection and a physician-reviewed report. You can also build a custom panel and pay only for the markers you choose.
Yes. A DHA-licensed phlebotomist can collect your sample at home or the office anywhere in Dubai at no extra cost, 7 days a week. See how it works.
It is commonly chosen by adults planning a family. If you are not sure it is right for you, our care team is happy to advise.
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Yes. It is processed at our EIAC-accredited laboratory (ISO 15189:2022) under DHA license 0046381 and verified by board-certified pathologists.
Every report includes reference ranges and plain-language notes. If you have questions, our care team can arrange a clinician review — just get in touch.
Absolutely. Add it to a curated health package or bundle it with any of our 160+ biomarkers, often from a single sample in one visit.