Testosterone is the predominant “male” hormone or androgen made in the human body, although both men and women need and utilize testosterone.
In men, testosterone is made in the testes. It plays a major role in regulating sperm production and is active throughout the body, impacting many areas of health including bone and muscle health/mass, libido, fat distribution, heart health, blood sugar metabolism, and hair growth/distribution. Testosterone declines with age in both men and women, but its level can also go up or down for other reasons.
After age 40, men lose about 1.5 percent of their testosterone production each year, and by age 45 about 40 percent of men will have a diagnosable low testosterone level (too low for their age and producing symptoms). Other causes of low testosterone levels in men include diseases of the liver or kidney, injury or infection of the testicles, diabetes, insulin resistance, obesity, genetic disorders (such as Klinefelter syndrome or hereditary hemochromatosis), pituitary tumors, and some prescription medications.
Women also need testosterone in small quantities to maintain good reproductive health. In women, testosterone is made in the ovaries and the adrenal glands, so a low level of testosterone can indicate a problem with the function of either organ, or it can be indicative of a normal decline from aging. Testosterone has many protective functions in females, including mitigating bone and muscle mass loss, supporting weight management, helping to maintain mental health, and supporting a healthy libido.
On the other hand, a woman’s testosterone level can be too high, particularly in women of childbearing age. An elevated testosterone level, often coupled with a low sex-hormone binding globulin level, is often associated with polycystic ovary syndrome (PCOS) and infertility.
Sex Hormone-Binding Globulin (SHBG)
Having a normal SHBG level is an important part of having a normal testosterone level in both men and women. SHBG is a protein that attaches to circulating testosterone and carries it around the body. Every individual always has some portion of their testosterone that is bound to SHBG, as well as a portion of their testosterone that is unbound or “free.” SHBG can also bind to estrogen, although it does not bind as tightly as it does to testosterone.
An elevated SHBG level will result in more of it attaching to testosterone, thus lowering the amount of free testosterone, whereas a low SHBG level can present as having relatively higher “free” testosterone.
Because SHBG is produced in the liver, its level can be decreased as a result of heavy alcohol consumption, obesity, insulin resistance, diabetes, aging, and the use of some prescription medications (especially hormones such as testosterone or estrogen).
You should take this test if you:
Notice unfavorable changes in body composition
Have loss of libido
Are a male experiencing erectile dysfunction
Are a female taking hormone replacement or using hormones for birth control
Are experiencing chronic fatigue or mood swings
Are a man or woman over 40
Are a woman of childbearing age with fertility issues
Are experiencing abnormal hair growth or loss
Testosterone • Blood Spot
Normal range varies based on age and gender
Testosterone is the predominant androgen or “male hormone” – although it is important to the health of both men and women. Testosterone impacts a wide range of health concerns, including muscle and bone mass, libido, hair growth, energy, mood, and sleep.
SHBG • Blood Spot
Normal range varies by gender
Sex hormone-binding globulin (SHBG) is a protein produced in the liver that binds to testosterone (and estrogen to a lesser extent). The extent of this binding by SHBG will change the amount of “free” or bioavailable testosterone, and thus can result in a deficiency or an excess of free testosterone. A low SHBG level is also associated with other health risks, independent of its impact on testosterone.
How it works
1 • Delivered
After purchasing, all home-test materials are delivered to your door
2 • Locate Barcode
Locate the barcode included with your kit and enter at thorne.com
3 • Complete Collection
Complete your test collection and return with prepaid shipping
4 • Reviewed
Your results are reviewed by an independent board-certified physician
5 • Receive Results
You’ll receive your results & personalized recommendations within 7-9 days
In men, if your testosterone level and/or SHBG level are abnormal for your age, then you can experience one or more of the following symptoms:
Heightened or reduced libido
Infertility or low sperm count
Muscle loss and/or weakness
Depressed mood or increased aggression
Changes in body and facial hair, or male pattern baldness
Development of breast tissue
In women, if your testosterone level and/or your SHBG level are abnormal for your age and menstrual status, then you can experience one or more of the following symptoms:
Muscle weakness or fatigue
Facial hair growth or thinning head hair
Difficulty getting pregnant
Abnormal menstrual cycles Test
What the tests tell you
Simple visualization of your biomarker results over time, plus detailed descriptions of each biomarker for an easy interpretation of your overall health.
Insights based on your results help you identify potential health risks or areas of improvement.
Access your diet, activity, and supplement plan anytime, anywhere through the Thorne dashboard. Recommendations are generated from our medically-supervised algorithms based on your unique test results.