SHBG (Sex Hormone Binding Globulin) Levels Blood Test

SHBG (sex hormone binding globulin) is a protein made mainly by the liver that attaches to sex hormones in the blood and controls how much is free to act on tissues. This blood test measures the amount of SHBG, usually to help interpret testosterone or estrogen levels when symptoms suggest a hormone imbalance.

What it measures

SHBG level — The amount of sex hormone binding globulin protein in the blood.
Calculated free testosterone — Sometimes derived from SHBG plus total testosterone to estimate hormone not bound to protein.
Total testosterone — Often measured alongside SHBG to give context to the SHBG result.
Estradiol — May be included when estrogen-related symptoms are being evaluated.

Who it is for

A clinician such as a primary care provider, endocrinologist, or gynecologist typically orders this test when hormone symptoms or unusual testosterone/estrogen results need clarification.

Preparation

No fasting is usually required, but timing may matter because SHBG can vary with the menstrual cycle and with some medications. Tell your clinician about hormones, thyroid medicines, or other prescriptions before testing.

Results and what they mean

Results are reported as a concentration in the blood, often with a reference range from the laboratory. Your clinician interprets the number alongside your symptoms, other hormone tests, and medical history; this is general information, not medical advice.

How to order this test

Choose the test and place a confidential order online.
Select a certified collection site and pick a time that suits you.
Have your specimen collected — most draws take only a few minutes.
Review results in a secure portal, typically within 1–3 days.

Preparation, hours, and pricing vary by site; confirm details directly with the lab before your visit.

Availability by state

Direct-access online ordering for the shbg (sex hormone binding globulin) levels blood test is available in most states. It is currently unavailable in 6 states:

Everywhere else you can order confidentially and collect your sample at a certified site. Browse by state →

Frequently asked questions

What can change my SHBG level?

Liver function, thyroid hormone, body weight, age, and some medications can affect SHBG, so results are read in context.

Do I need to fast?

Fasting is usually not required, but follow any instructions your clinician gives.