SHBG (Sex Hormone-Binding Globulin)
SHBG is a liver protein that binds testosterone and estradiol in blood. It determines how much free (active) hormone is available to tissues.
Normal ranges
Men: 10–57 nmol/L. Women: 18–144 nmol/L (lab-specific).
Units: nmol/L
Causes of deviations
Low levels:
Obesity, insulin resistance, hypothyroidism, androgen excess.
High levels:
Hyperthyroidism, liver disease, aging, estrogen therapy.
When to see a doctor
If testosterone is borderline or symptoms don't match total hormone levels.
This information is for educational purposes and does not replace medical advice.
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