Testosterone & SHBG
Also known as:
Total testosterone, free testosterone, sex hormone-binding globulin
How to test testosterone properly: morning, fasting, repeated, and interpreted with SHBG.
Written and reviewed by Farhan Tahir, MD · Last reviewed
VIDEO LESSON
What it measures
Total testosterone includes hormone bound to SHBG and albumin plus a small free fraction. SHBG levels change how much testosterone is available to tissues.
How to test
• Draw blood in the early morning, ideally fasting
• Repeat a low result before diagnosing deficiency
• Avoid testing during acute illness
• Use mass spectrometry (LC-MS/MS) where possible, especially for women
Reading SHBG
SHBG rises with age, hyperthyroidism, liver disease and oral estrogen, which can hide low free testosterone. It falls with obesity, insulin resistance and type 2 diabetes, which can make total testosterone look low when free testosterone is normal. Calculated free testosterone helps in both cases.
In women
Testosterone helps assess PCOS and androgen excess, and is used to monitor women on transdermal testosterone so levels stay in the premenopausal range. It does not diagnose low desire.
Key studies and references
Trusted resources
Educational content only, written and reviewed by Farhan Tahir, MD. It does not replace individual medical advice. For sudden chest pain, trouble breathing or stroke symptoms, call 911.
AT A GLANCE
Test type
Sex hormones
Also known as
Total testosterone, free testosterone, sex hormone-binding globulin
Reviewed by
Farhan Tahir, MD
Questions about your own care?
Dr. Tahir’s team offers consults through Youthful Medicine.
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