Androgens . Patient guide
Sex Hormone Binding Globulin (SHBG) Blood Test
What is SHBG
SHBG is the carrier protein that binds testosterone and oestradiol in the bloodstream and controls how much is biologically available to tissues. SHBG is essential for calculating the free testosterone fraction from a total testosterone result.
This biomarker entry is being clinically reviewed by our team. The factual content draws on UK guidance (NICE, NHS, Royal Colleges and the relevant speciality society where cited).
Reference range
Reported in nmol/L. Final reports always carry the issuing laboratory's range, which is what your clinician will interpret against.
| Group | Range | Note |
|---|---|---|
| Adult men | 18 to 54 | nmol/L |
| Cycling women | 32 to 128 | |
| Postmenopausal women | 27 to 128 |
What it is
SHBG is made by the liver and binds tightly to testosterone and oestradiol, sequestering them from receptor binding until released. Only the free fraction (around 1 to 2 percent of total) is biologically active. SHBG is therefore not a hormone in its own right but the regulator that turns a total testosterone reading into a clinically meaningful free testosterone reading.
Why a clinician would order it
SHBG is requested whenever total testosterone is measured (to calculate free testosterone), in the work-up of androgen excess in women (low SHBG raises free testosterone effect for any given total), in metabolic risk assessment (low SHBG is an independent marker of insulin resistance), and in suspected hyperthyroidism or hypothyroidism (thyroid status shifts SHBG up or down respectively).
If your level is outside the range
Symptoms of low SHBG
- Symptoms typically reflect raised free androgen effect: acne, hirsutism, scalp hair thinning (women), oily skin
- Often clustered with insulin resistance: central weight gain, afternoon energy slumps
What low can indicate. Insulin resistance (the commonest non-androgen cause), PCOS / PMOS, obesity, hypothyroidism, exogenous androgen use (TRT, anabolic steroids), Cushing's syndrome.
Symptoms of high SHBG
- Symptoms typically reflect reduced free androgen effect: low libido, fatigue, reduced muscle mass (men particularly)
What high can indicate. Hyperthyroidism, oral oestrogen (oral contraceptive or HRT), pregnancy, liver disease (cirrhosis), anorexia or significant weight loss, ageing (SHBG rises with age in men).
Testing tips
No fasting required. Hold oral oestrogen-containing contraceptives or HRT for at least 6 weeks if a true baseline is needed (they sharply raise SHBG). Always interpret alongside total testosterone so the calculated free testosterone can be derived: most labs report this automatically. SHBG also moves with thyroid status, so abnormal results merit a TSH check.
Where you can get this tested
Sex Hormone Binding Globulin is included in the following WMG Health panels. Same-day appointments at our Harley Street clinic, with results clinician-reviewed.
Want a specific combination of markers we do not have a panel for? Build a custom panel and our clinicians will design one for you.
Looking to book a test?
Private testosterone blood test
Total + free testosterone, SHBG, LH, FSH and DHT, drawn fasting 7 to 11 AM per BSSM guidance.
Symptoms often investigated with Sex Hormone Binding Globulin
Sex Hormone Binding Globulin is commonly tested when patients present with the following symptoms. If any of these resonate with you, the linked guides explain what to look for and which test pathway is appropriate.
Read this marker alongside another
Sex Hormone Binding Globulin is most useful when interpreted together with the markers below. Each guide walks through the 4-quadrant matrix our clinicians use when both come back at once.
Sources
UK guidance our clinicians use when interpreting this marker.
This page is general patient information, not personal medical advice. A GMC-registered clinician will review your results and tailor any interpretation to you. See our Editorial Policy for how we write and review content.
Common questions about SHBG
What is a normal SHBG range?
Adult men: 18 to 54 (nmol/L). Cycling women: 32 to 128. Postmenopausal women: 27 to 128. Always interpret your own results against the laboratory range printed on your report, since assay-specific reference ranges vary.
What does a low SHBG result mean?
Insulin resistance (the commonest non-androgen cause), PCOS / PMOS, obesity, hypothyroidism, exogenous androgen use (TRT, anabolic steroids), Cushing's syndrome.
What does a high SHBG result mean?
Hyperthyroidism, oral oestrogen (oral contraceptive or HRT), pregnancy, liver disease (cirrhosis), anorexia or significant weight loss, ageing (SHBG rises with age in men).
Do I need to fast or prepare for the SHBG blood test?
No fasting required. Hold oral oestrogen-containing contraceptives or HRT for at least 6 weeks if a true baseline is needed (they sharply raise SHBG). Always interpret alongside total testosterone so the calculated free testosterone can be derived: most labs report this automatically. SHBG also moves with thyroid status, so abnormal results merit a TSH check.
Can I order a SHBG blood test privately in London?
Yes. WMG Health offers SHBG as part of bespoke panels and several pre-built panels at our 134 Harley Street clinic. Results are clinician-reviewed by a GMC-registered doctor within 4 hours for the most common assays. All panels are custom-built around your specific question; bookings via /contact/ or 020 3239 3378.