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High Sex Hormone Binding Globulin

Updated on July 8, 2021
Written by
Joel
2 sources cited
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Hormone testing tells you a lot about the health of your body. Unbalanced hormones affect your health and well-being, but sometimes it’s difficult to recognize the issue. You might feel less-than-your-best or struggle with issues seemingly unrelated to your hormones. In some cases, people dismiss their nagging health issues and assume they are just getting older. Little do they know, if they took a hormone test they’d be better able to identify imbalances and find ways to improve their health.

One of the most popular hormone tests is the sex hormone binding globulin test. This test evaluates testosterone and other sex hormones. How might this test help you improve your health?

What is the Sex Hormone Binding Globulin?

Sex hormone binding globulin (SHBG) is a protein made by the liver. It binds to three sex hormones – estrogen, testosterone, and dihydrotestosterone (DHT), all three of which are found in both men and women. Once bound, SHBG carries the three hormones throughout the body via the bloodstream.

Taking a sex hormone binding globulin test helps you evaluate testosterone levels in your body. SHBG controls how much testosterone bodily tissue can use.

Problems occur when men don’t have enough testosterone and women have too much. SHBG levels fluctuate with age. Factors including liver health, thyroid health, and obesity also affect SHBG levels.

People test SHBG levels for a couple of different reasons. If you or your doctor suspects your testosterone levels are out of balance, the SHBG test helps diagnose the cause. For example:

Androgen Deficiency

If a man's androgen hormone levels are too low, he’ll experience sexual problems and general weakness. If androgen is out of balance in women, it affects their bone strength and thought clarity. It also interferes with ovary function.

Hypogonadism

Hypogonadism typically only occurs in males. It happens if sperm and/or testosterone production is too low.

How Does SHBG Work?

SHBG is a binding agent. You need to have just enough of it to ensure everything is working properly in your body hormone-wise. The substance grabs onto free-floating hormones in your body, so too much and there won’t be enough free hormones to work and too little and your hormone levels are too high.

Even small changes to the levels of SHBG in your body can cause serious health problems.

SHBG has an affinity to specific sex hormones. The order of preference is as follows:

  • Dihydrotestosterone (DHT)
  • Testosterone
  • Androstenedione
  • Estradial
  • Estrone

Too much SHBG in men and women results in symptoms of low testosterone, including:

  • Depression
  • Weight gain
  • Irritability
  • Loss of muscle mass

Too little SHBG in women cause testosterone levels to spike, leading to:

  • Facial hair growth
  • Polycystic ovarian syndrome (PCOS)
  • Weight gain
  • Acne
  • Irritability

Keep in mind, many doctors don’t think to test SHBG levels. They might test testosterone levels or other hormones, but don’t additionally test SHBG. This is one of the most important tests you can undergo if you are experiencing any health issues that might be related to hormones. If your doctor does not suggest this test or you are not sure if you’ve undergone this test, ask for more information.

What are the Symptoms of High SHBG?

The sex hormone binding globulin test can determine if levels of testosterone are too high. A high result from the test means SHBG protein is attaching to too much testosterone. When this happens, it means there is not enough “free” testosterone available and your body’s tissues don’t get enough of the hormone.

High SHBG can be an indicator of:

  • Liver health issues
  • Pregnancy
  • Hyperthyroidism
  • Eating disorders, especially anorexia nervosa
  • Hormone replacement therapy
  • Hypogonadism
  • Problems with the pituitary gland or testicles
  • Addison disease

In addition to the SHBG test, doctors might also order estrogen and testosterone tests. The test results help you determine the issue and give you a starting point for better managing your hormones.

What are the symptoms of low testosterone in men?

  • Low sex drive
  • Fertility problems
  • Difficulty getting an erection

What Causes High SHBG Levels?

A person’s level of SHBG depends on two things:

  • Thyroid hormone
  • Estrogen levels

A problem with either of these increases the circulating sex hormone binding globulin in the blood.

When a woman has high levels of SHBG, it’s usually linked to the body using too much estrogen. This is a result of estrogen dominance or the use of oral contraceptives or any other forms of hormonal birth control. There might also be other hormones triggering a problem with SHBG. 

Using hormone supplements can trigger a problem with SHBG, so make sure you address any concerns with your doctor if you experience negative changes while using hormone therapy.

Changes in SHBG affect how much free testosterone there is in your body. This is one reason why women using some types of hormone therapy tend to experience mood changes and gain weight.

People taking T3 medications or undergoing aggressive thyroid hormone replacement therapy, also experience problems with SHBG. T4 medications can also cause a rise in SHBG.

What Can You Do If You Think You Have a Hormonal Imbalance?

There are many things you can do if you have high or low levels of SHBG.

If your sex hormone binding globulin is high, you should speak to your doctor about what can be done to bring things into balance. If you aren’t sure and you suspect you might have a hormonal imbalance, ask your doctor for an SHBG test. Too little or too much of any sex hormone can cause short-term and long-term health problems, so it’s important to do what you can to achieve proper balance.

If age is to blame for your hormonal imbalance, you can use supplemental hormone therapy to treat the issue. Postmenopausal women and aging men often deal with hormone imbalances that affect their well-being. Hormonal fluctuations are normal with age, but you don’t need to live with the discomfort or unpleasantness they cause.

If you are younger and oral contraceptives or other forms of hormonal birth control are to blame, you should speak to your doctor about your options. Although effective, some types of birth control wreak havoc on your system and aren’t the best choice. You and your doctor can discuss your challenges and intentions to determine the best type of birth control for you.

Resources

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Selby, C. “Sex Hormone Binding Globulin: Origin, Function and Clinical Significance.” Annals of Clinical Biochemistry, vol. 27 ( Pt 6), 1990, pp. 532–41, www.ncbi.nlm.nih.gov/pubmed/2080856, 10.1177/000456329002700603.

“SHBG Blood Test: MedlinePlus Medical Test.” Medlineplus.gov, medlineplus.gov/lab-tests/shbg-blood-test/.

Joel
Content Contributor
Joel is a writer with a passion for the science of DNA and the power of its manipulation.
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