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SHBG is a protein in your blood that binds to sex hormones such as testosterone. A low level can suggest that more of your testosterone is free. A high level can suggest that your tissues are able to use less testosterone.[1]
On this page, you can read what SHBG is, what the guidelines say about a level that is too low or too high, what affects your level and which other levels are best looked at alongside it.
Also known as: sex hormone-binding globulin, testosterone-oestrogen binding globulin, TeBG. At the lab: SHBG.
SHBG stands for sex hormone-binding globulin. It is a protein made mainly in your liver. It binds to sex hormones such as testosterone and oestrogen. In this way, it helps determine how much of those hormones are active in your body.[1]
The sex hormones in your blood are either bound to proteins or free. Free hormones work with your tissues. They help, for example, with the growth of bones and muscles and with your fertility. Hormones that are attached to SHBG cannot do that.[1]
Testosterone is often called a male hormone, but women have it too, in smaller amounts. In everyone, it helps regulate your sex drive and contributes to the growth of muscle and bone.[1]
A total testosterone test measures free and bound testosterone together. That test cannot tell the two apart. So you can have symptoms of too little or too much free testosterone, even if your total testosterone is normal. SHBG helps your doctor estimate how much testosterone is free.[1]
In adult men, the test is often done for symptoms that may fit too little testosterone, such as a low sex drive, tiredness or less muscle mass. In adult women, it is more often about symptoms that may fit too much testosterone, such as a lot of hair growth on the face and body, acne or irregular periods.[1]
SHBG can also help identify a hormonal condition that affects the female reproductive system. The test alone is not enough for this: your doctor looks at it alongside other results. Your doctor can also use SHBG to follow how a level changes during your care.[1]
In children, SHBG is normally high. This means sex hormones still have little effect on the body. A low level in a child can point to puberty that starts too early.[1]
Labplusarts, the lab BioProfile works with, uses a reference value of 13.2 to 89.5 nmol/l for SHBG. The lab calls a level between those limits normal.[2]
| Value | What it can mean | Who it is for |
|---|---|---|
| 13.2 to 89.5 nmol/l[2] | Normal according to the lab | The lab does not name a separate group |
Source: Labplusarts, the lab BioProfile works with. The range applies to this lab's SHBG measurement.[2]
A level that is too low can suggest that more of your testosterone is free and can be used by your body. According to MedlinePlus, a low level can be linked to an underactive thyroid, a metabolic condition involving insulin, severe overweight, heavy use of steroids or anabolic steroids, another hormonal condition and, in women, a hormonal condition of the reproductive system. It is also normal for SHBG to fall as you get older.[1]
A level that is too high can suggest that your tissues are able to use less testosterone. According to MedlinePlus, a high level can be linked to a liver condition, an overactive thyroid, certain eating disorders, in women the use of medicines containing oestrogen such as the pill or hormone therapy during the menopause, and in men a lower production of sex hormones.[1]
BioProfile is working on its own zones for each value, from risk to optimal. A doctor reviews those zones before they appear in your result.
Medicines containing hormones, such as the pill, oestrogen therapy or anabolic steroids, can affect your SHBG. Tell your doctor which medicines, vitamins and supplements you take. Do not stop a medicine on your own unless your doctor tells you to.[1]
In children, SHBG is normally high. As you get older, SHBG often falls, because your body also makes fewer sex hormones by then.[1]
An underactive thyroid can go together with a lower level, and an overactive thyroid with a higher one. A liver condition can also go together with a higher level.[1]
Severe overweight and a metabolism that responds less well to insulin can go together with a lower SHBG level.[1]
SHBG is included in BioProfile 121 and 150.[3]
The BioProfile editorial team wrote this page on 10 October 2026 from the sources below, which we read on 10 October 2026. Every number on this page appears in one of those sources, with that source's number next to it. An expert has yet to check this page; after that check, the expert's name and the date of the check will appear at the top. This page offers explanation, not a diagnosis. Discuss a value outside the range with your GP.
