In This Article
In This Article
Hormones are essential in your body’s sexual development. For example, women need them to regulate their menstrual cycle during their reproductive years.
The body makes a protein that helps regulate and move your hormones in the bloodstream — the Sex Hormone Binding Globulin or SHBG.1
The level of SHBG in your body depends on many factors, including your age and gender. But an abnormally high concentration may indicate several disorders related to hormones.
Sex Hormone Binding Globulin, or SHBG, is an essential protein made by the liver. The testes also produce them in smaller amounts.
It binds to three sex hormones in your blood, which are
SHBG carries these hormones throughout your bloodstream. The primary role of SHBG is to control the number of free testosterone and estradiol available for use by your cells.
Your body can only use hormones that are unbound or free. Once SHBG binds to your sex hormones, they become inactive. SHBG regulates your hormone levels this way.
SHBG has a stronger affinity to male sex hormones or androgens like DHT and testosterone. They have a lesser bond to female hormones or estrogens like estradiol.
This makes the SHBG level crucial in keeping the balance of male and female hormones in a woman's body.
The normal level of SHBG depends on your gender and age. For example, women have naturally higher levels compared to men.
However, other factors can influence its concentration, such as:
In adults, the healthy SHBG concentration is 10 to 57 nmol/L in men and 18 to 144 nmol/L in non-pregnant women.
Your body’s SHBG level moves in a U-shaped pattern throughout your lifespan. It decreases when you’re between 20 and 60 years. After the age of 60, it will rise and continue to increase.
The leading causes of a high SHBG level are increases in estrogen levels and thyroid hormone levels. They can elevate the amount of circulating SHBG in the blood.
Other conditions are also linked to increased SHBG levels, such as liver issues.
High estrogen levels are associated with a high SHBG concentration in your blood. An increase in estrogen stimulates your liver to release more SHBG.
Your estrogen increases during the following events:
During pregnancy, SHBG increases slowly and becomes stable at around 24 weeks. When you're pregnant, your estrogen level rises, stimulating the production of SHBG in the liver.2
Your SHBG may also increase due to combined oral contraceptives. Pills that have estrogen triggers the liver to make more of it.
Your thyroid hormones are essential for breaking down and synthesizing many complex molecules. It also dictates the production of SHBG.3
A study shows that a high SHBG level is associated with hyperthyroidism. Taking thyroid medication can help reduce thyroid hormones and SHBG levels.
The liver is mainly responsible for SHBG production. When it is damaged, it can lead to abnormal SHBG levels.
Liver conditions such as hepatitis, liver cirrhosis, and iron overload are linked to high SHBG levels.
The symptoms of high SHBG are similar to the signs of low testosterone in men and low estrogen levels in women.
Since SHBG decreases the available hormones in your bloodstream, a high SHBG level means it's attaching too much to your sex hormones.
Men and women with high SHBG may have different symptoms. However, both may experience infertility, a lower sex drive, decreased energy levels, and reduced bone and muscle mass.
A doctor can help determine your SHBG levels more accurately.
In men, a high SHBG level includes the following signs:
In women, abnormal increases in SHBG may have the following symptoms:
Taking an SHBG test helps evaluate your SHBG and your sex hormone levels. It’s because SHBG controls the distribution of sex hormones throughout your body.
This test checks for SHBG proteins from a blood sample. If your doctor suspects abnormal testosterone levels, they might order an SHBG test and a testosterone test to be sure.
For men, you may have testosterone levels that are too low. For women, it may mean you have too much testosterone.
The SHBG blood test isn't usually a part of a routine check-up. But your doctor might ask you to take this test to rule out the following:4,5
You don’t need to live with elevated SHBG. Talk to your doctor so they can identify your normal range and perform tests to confirm the cause of your symptoms.
If you have too much SHBG, they might prescribe medications and other treatments that will help you manage it. In some cases, lifestyle changes can help reduce your SHBG levels.
Research suggests that your fiber and protein intake may affect your SHBG levels.6 Older adults (especially men) who eat low-protein diets have high SHBG.
Adding more protein-rich foods to your meals may help decrease your SHBG. If you eat meat, go for grass-fed and organic meat sources.
Several supplements show promising results in lowering high SHBG levels. These include:
However, further clinical studies are still needed to prove their effectiveness.
You may be using contraceptives that mess up your hormone levels. In this case, you can talk to your doctor about your options. They can help determine the best type of birth control for you.