Sex Hormone Binding Globulin, also known as SHBG, is a glycoprotein that most of us have never heard of. Since SHBG is related to testosterone and other sex hormones, many women remain in the dark about their SHBG status. But SHBG is an important biomarker for women to pay attention to. SHBG typically isn't included in standard bloodwork, but InsideTracker includes it in both the Ultimate and Foundation plans. Read more to find out more about this biomarker and what levels indicate.
What is Sex hormone binding globulin (SHBG)?
SHBG is a glycoprotein, a molecule that consists of a carbohydrate plus a protein, and is produced mainly in your liver. It binds to three sex hormones found in both men and women: estrogen, dihydrotestosterone (DHT) and testosterone. Its job is to transport these hormones throughout your blood to other tissues in your body. SHBG has a stronger affinity for DHT and testosterone (which are androgens), as compared to estrogens. It therefore plays a significant role in maintaining the delicate balance between estrogen and testosterone in a woman’s body.
The importance of optimal SHBG levels for womenTestosterone and other hormones play an important role in a woman’s overall physical and emotional health. As a woman, you may have experienced times in your life when you knew your hormones were out of whack. SHBG makes sure that these hormones are transported throughout your body and are available for the tissues that need them. Optimal SHBG levels decrease a woman’s risk of developing polycystic ovarian syndrome, insulin resistance and type 2 diabetes.
What causes low SHBG levels in women?SHBG levels decrease as a result of taking certain hormones like androgens (i.e. testosterone), anabolic steroids, and norethisterone-related synthetic progesterones. Certain conditions, like hypothyroidism, obesity, Cushing’s syndrome, and acromegaly (a condition where your body produces too much growth hormone), can also cause low SHBG levels. Interestingly, insulin resistance, even without obesity, results in lower SHBG levels.
Women with low levels of SHBG are more likely to have higher testosterone levels, which can lead to androgenization, i.e. the development of masculine characteristics. Low SHBG is often associated with polycystic ovarian syndrome. Other signs of low SHBG in women include: high levels of androgens, male-patterned hair growth or hair loss, menstrual irregularities, decreased breast tissue and skin abnormalities. Women with low SHBG are also at higher risk for developing cardiovascular disease, type 2 diabetes and metabolic syndrome.
What causes high SHBG levels in women?Compared to men, women naturally have higher levels of SHBG. The aging process, particularly for women, increases SHBG levels, which means younger women tend to have lower SHBG levels than postmenopausal women. Pregnancy increases SHBG even further, as SHBG is actually produced in the placenta tissue. Some evidence suggests that continuous use of oral contraceptives can also increase your SHBG levels. Finally, undernourishment, as seen in anorexia nervosa, and estrogen or thyroid hormone treatment can cause higher than normal SHBG levels in women.
Women with high levels of SHBG have less available testosterone in their bodies. That’s bad news since testosterone (another biomarker measured by InsideTracker) plays an important role in maintaining energy levels, muscle development, bone health, and your sex drive.
SHBG is an important biomarker… but it’s just one piece of the puzzle in the roadmap to optimal health for women. InsideTracker can help provide you with more of the whole picture by analyzing your levels of 47 blood biomarkers related to optimal wellness, including estradiol, progesterone, DHEAS, and thyroid-stimulating hormone.