SHBG (Sex Hormone Binding Globulin)
This test measures sex hormone binding globulin (SHBG), a protein that regulates the amount of biologically active testosterone and estrogen available to the body.
Select Lab Partner
What this test measures
Sex hormone binding globulin (SHBG) is a protein produced mainly in the liver that serves as a crucial transport system for sex hormones in the blood. SHBG binds (attaches) to sex hormones such as testosterone and estrogen and helps control how much of these hormones are active in your body. The protein acts like a molecular taxi service, carrying hormones throughout the bloodstream while keeping them in an inactive, bound state until they're needed.
Hormones in this bound state aren't available for cells to use, making SHBG a key regulator of hormone availability. When SHBG levels are low, the body has more unbound sex hormones available for use. When SHBG levels are high, the body has fewer free sex hormones at its disposal. This delicate balance affects numerous bodily functions, including metabolism, reproductive health, muscle development, and energy levels. SHBG testing is particularly valuable for understanding how much biologically active testosterone or estrogen is circulating in the body, regardless of total hormone levels.
Who should consider this test
You might consider this test if you are experiencing any of the following:
- Individuals experiencing symptoms of hormone imbalance, such as unexplained fatigue, changes in muscle mass, or altered mood
- Individuals being evaluated for hirsutism in women and for infertility, reduced libido or erectile dysfunction in men, particularly when androgen levels are within normal ranges
- Women suspected of having polycystic ovary syndrome (PCOS) or experiencing irregular periods, acne, or excess hair growth
- Individuals with metabolic conditions like obesity, insulin resistance, or type 2 diabetes that may affect hormone balance
- Those taking hormone therapy or medications that might influence sex hormone levels
- Individuals with thyroid disorders, as these conditions can significantly impact SHBG production
What to expect
Preparation
No special preparation is typically required for this test. Individuals should inform their healthcare provider about any medications, supplements, or hormone therapies they are taking, as these may affect results. The test can be performed at any time of day and does not require fasting.
Sample Type
This test requires a simple blood draw from a vein, typically in the arm.
Collection
The blood sample collection takes just a few minutes at the lab. A healthcare professional will clean the area, insert a small needle to draw blood into a tube, and apply a bandage afterward. Most individuals experience minimal discomfort.
Turnaround
Results are typically available within 1-2 business days after the lab receives the sample.
Understanding your results
SHBG results are reported in nanomoles per liter (nmol/L) and indicate how much of this transport protein is circulating in the blood. Changes in SHBG levels can affect the amount of hormone that is available to be used by the body's tissues. Results should be interpreted alongside symptoms and other hormone tests for a complete picture of hormonal health.
| Population | Reference Range | Notes |
|---|---|---|
| Adult Males | 10-57 nmol/L | Men's SHBG levels usually increase with age as testosterone levels naturally decline |
| Adult Females (Non-pregnant) | 18-144 nmol/L | Women typically have higher SHBG levels than men |
| Pregnant Women | Elevated above normal range | SHBG is also produced by placental tissue and values will be elevated during pregnancy |
Reference ranges shown are general guidelines. Your lab report will include the specific reference range used by the laboratory that processed your sample, which is the authoritative range for interpreting your results.
What does a “Low” result mean?
Decreased SHBG levels can be associated with obesity, hyperinsulinemia, hypothyroidism and growth hormone excess, as well as with glucocorticoids, androgens, and progestins. Low serum SHBG levels are considered a biomarker of abnormal metabolism and are related to insulin resistance, compensatory hyperinsulinemia and abnormalities in glucose and lipid metabolism. Lower serum SHBG levels are associated with the risk of PCOS, and low SHBG means more free testosterone circulating in the bloodstream, which can worsen PCOS symptoms like hirsutism (excess hair growth), acne, and irregular periods. Low levels may also indicate increased risk for metabolic syndrome and type 2 diabetes.
What does a “High” result mean?
Increased SHBG levels can be associated with anorexia, pregnancy, aging, growth hormone deficiency, androgen deficiency, hyperthyroidism, liver disease, hyperprolactinemia, active porphyria and also with estrogens. Thyrotoxicosis increases SHBG concentrations, and elevated levels may suggest tissue thyrotoxicosis in certain clinical situations. Higher SHBG levels typically mean that less free testosterone and estrogen are available for the body to use, which may contribute to symptoms like reduced libido, fatigue, or decreased muscle mass. In the long term, SHBG on the high end of the normal range can have a protective effect on the heart and may decrease prostate cancer risk, but it may be linked to weakened bones in elderly individuals.
Privacy & confidentiality
All test orders are authorized and results reviewed by an independent, board-certified physician who is not the patient's personal doctor. Your SHBG test results are completely confidential and handled with the utmost discretion. Results are <u>not reported to your doctor</u> unless you specifically request it, and they are <u>not part of your medical records</u> maintained by healthcare providers. The test is <u>not covered by insurance</u>, so there are no insurance claims or explanations of benefits that could reveal your testing. Results are <u>not on insurance statements</u> or shared with employers, family members, or government agencies. The testing process is designed to protect your privacy at every step. You can order the test online discreetly, visit any lab location without an appointment, and receive your results securely through an encrypted online portal. Many individuals choose private hormone testing to understand their health status confidentially, whether for personal knowledge, before consulting with a healthcare provider, or to monitor changes over time without creating a medical record.
Frequently asked questions
Related tests
Testosterone, Total
$69Often ordered together with SHBG to calculate free testosterone and assess overall androgen status
View TestTestosterone, Free
$79Measures biologically active testosterone that is not bound to SHBG or other proteins
View TestInsulin, Fasting
$39Insulin resistance can suppress SHBG production and is commonly evaluated alongside SHBG testing
View TestRelated conditions
CPT Code: 84270
This test may not be available in: NY, NJ, RI
This page is for informational purposes only and does not constitute medical advice. Always consult with a healthcare provider regarding any health concerns. LevelPanel does not diagnose, treat, or prescribe.
Select Lab Partner
Not sure if this is the right test? Contact our care team for guidance.