SHBG
A liver protein that binds testosterone and estradiol, controlling how much is freely available.
| Typical reference range (male) | 10–50 nmol/L |
| Typical reference range (female) | 17–124 nmol/L |
Ranges vary by laboratory, method, age and sex: always use the range printed on your own report. Why labs differ.
What it measures
Sex hormone-binding globulin is produced by the liver and binds testosterone tightly and estradiol less tightly. Hormone bound to SHBG is largely inactive.
Why it matters
SHBG determines how total testosterone translates into free testosterone. Low SHBG is also a marker of insulin resistance and predicts type 2 diabetes risk.
What a high result can mean
High SHBG occurs with aging, hyperthyroidism, estrogen and oral contraceptive use, liver disease, low body weight, calorie restriction, anticonvulsants and HIV.
What a low result can mean
Low SHBG occurs with insulin resistance, obesity, type 2 diabetes, fatty liver, hypothyroidism, PCOS, androgen or anabolic steroid use, glucocorticoids and nephrotic syndrome.
What affects the result
Weight loss and improved insulin sensitivity raise SHBG; high insulin suppresses it. Oral estrogen raises it substantially. Interpret with total and free testosterone and estradiol.
Unit
Usually reported in nmol/L.
Also called on lab reports
Sex Hormone Binding Globulin, Sex Hormone-Binding Globulin, Sex Horm Binding Glob, Serum, Sex Hormone Binding Globulin, Serum
Related tests: Sex Hormones
This page is educational and does not replace advice from a healthcare professional.