SHBG is a protein that binds testosterone and estrogen in your blood. Understanding SHBG levels helps interpret how much sex hormone is actually available for your body to use.
Sex Hormone Binding Globulin (SHBG) is a protein produced primarily by the liver that binds to testosterone, dihydrotestosterone (DHT), and estradiol in the bloodstream. Hormones bound to SHBG are inactive—only "free" hormones can enter cells and exert their effects.
SHBG levels significantly impact how much active hormone is available to your tissues. High SHBG means more hormone is bound and unavailable; low SHBG means more free hormone is circulating. This is why SHBG testing is essential for properly interpreting testosterone and estrogen results.
SHBG is influenced by many factors: it increases with aging, estrogen, hyperthyroidism, and liver disease. It decreases with obesity, insulin resistance, high androgens, and hypothyroidism.
Price
$16
Results
2-3 days
Lab Network
Quest
Fasting
Not Required
What's Measured
What This Test Measures
This test measures the concentration of SHBG protein in your blood, reported in nmol/L. Combined with total testosterone, SHBG can be used to calculate free testosterone levels.
Who Should Consider This Test
Men with low testosterone symptoms but normal total testosterone, women with signs of excess androgens (acne, hair growth), anyone with borderline hormone results, people with metabolic syndrome or insulin resistance, and those on hormone therapy.
Health Insights
Conditions Screened
Related Symptoms
When to Get Tested
No fasting required. For most accurate results, test in the morning when testosterone levels are highest. SHBG is relatively stable throughout the day.
Understanding Your Results
Normal ranges vary by sex: Men: 10-57 nmol/L, Women: 18-144 nmol/L. High SHBG can cause low free testosterone despite normal total testosterone. Low SHBG is associated with insulin resistance and may indicate PCOS in women.
What to Expect
After placing your order, you'll receive an email from Rupa Health (our lab order partner) within 24 business hours to sign a consent form and schedule your blood draw at a Quest Diagnostics location.
The blood draw typically takes just a few minutes. Results are usually available within 2-3 business days and will appear in your secure Justlabs dashboard.
Our results include reference ranges and easy-to-understand indicators showing whether your values are within normal limits.
Frequently Asked Questions
$16
Typical hospital cash price: $120–$180
+ $28 in standard lab & physician fees at checkout (no additional bills later)
$18 lab collection + $10 physician order
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