What this marker measures
SHBG is most useful when interpreted together with total testosterone — it lets clinicians calculate free testosterone and decide whether a borderline total testosterone is clinically meaningful.
High or low: what it can mean
High SHBG
High SHBG is seen with hyperthyroidism, liver disease, oestrogen therapy, and pregnancy. High SHBG lowers the free fraction of sex hormones, which can produce symptoms even when total levels look normal.
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Low SHBG
Low SHBG is associated with insulin resistance, type 2 diabetes, obesity, and PCOS. Low SHBG raises the free (active) fraction of androgens, contributing to hyperandrogenic symptoms in females.
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Frequently asked questions
What is SHBG?
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SHBG is a protein made in the liver that binds testosterone and estradiol in the bloodstream, regulating how much of each hormone is biologically available.
What does SHBG measure?
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SHBG is most useful when interpreted together with total testosterone — it lets clinicians calculate free testosterone and decide whether a borderline total testosterone is clinically meaningful.
What does high SHBG mean?
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High SHBG is seen with hyperthyroidism, liver disease, oestrogen therapy, and pregnancy. High SHBG lowers the free fraction of sex hormones, which can produce symptoms even when total levels look normal.
What does low SHBG mean?
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Low SHBG is associated with insulin resistance, type 2 diabetes, obesity, and PCOS. Low SHBG raises the free (active) fraction of androgens, contributing to hyperandrogenic symptoms in females.
Related biomarkers
Editorial note
LabTestly explains lab markers using plain-English educational content. Reference ranges may vary by laboratory and should be interpreted with a clinician.
Educational content · Editorially reviewed for clarity · Last updated
Common sources used for lab-test education
Not medical advice
This page is for general understanding only and does not replace medical advice from your clinician. Reference ranges can vary by laboratory, age, sex, pregnancy status, medications, and clinical context.