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Testosterone Testing 101

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Testosterone Testing 101

The effects of testosterone have been known to man long before testosterone was identified. In China since the 1300s, castrated men served prominent positions in the Chinese imperial court, as they were more obedient. Islamic countries used castrated enslaved people in battles for the same reasons. Testosterone can impact brain function, sexual characteristics, and energy levels in both men and women.

This article will discuss testosterone's role in the body, high and low testosterone symptoms in both males and females, how to test it, and functional medicine treatments for testosterone imbalances.


What is Testosterone?

Testosterone is an essential hormone for both men and women. In men, testosterone levels peak during puberty and decline by one to two percent each year starting in the third decade of life. Testosterone is made by activating the Hypothalamic Pituitary Gonadal (HPG) axis. The hypothalamus (in the brain) secretes gonadotropin-releasing hormone (GnRH). GnRH signals the pituitary gland to release Luteinizing Hormone (LH), which acts upon the Leydig cells in the testicles, causing them to produce testosterone. The level of circulating testosterone will send a feedback signal to the hypothalamus, with high levels causing suppression of the release of GnRH and low levels doing the opposite. This is called a negative feedback loop.

In women, testosterone is made in the ovary from the prohormone DHEA (made in the adrenal glands). Testosterone is converted into estradiol, one of the primary female hormones. In fact, ovaries produce three to four times more testosterone than estrogen, making it the true dominant hormone in women. Testosterone levels peak in the 30s and 40s before declining.

In both men and women, testosterone is released on a daily cycle, with levels peaking in the morning and tapering throughout the day. Entering into the circulation, testosterone is carried through the body by a carrier molecule, sex hormone binding globulin (SHBG). Testosterone can convert into dihydrotestosterone (DHT) via the enzyme 5alpha-reductase. DHT is more potent than testosterone, and because of this, there are targeted therapies to inhibit the 5alpha-reductase enzyme and thus lower DHT levels. Testosterone can also convert into estrogens primarily in the fat tissue by the aromatase enzyme. Like 5alpha-reductase, pharmaceutical compounds can inhibit the aromatase enzyme to lower estrogen production.  

What is Testosterone's Role in The Body?

In men, testosterone is responsible for producing both primary and secondary sex characteristics. Primary sex characteristics include sperm production, testicular and penile development, and increased libido. Secondary sex characteristics include voice changes, hair growth, and skeletal and muscle development. Testosterone also induces the formation of red blood cells and can also affect muscle mass, endurance, energy, and erections.

As discussed above, testosterone's primary role in women is to convert into estradiol. However, testosterone also influences primary and secondary sex characteristics such as clitoral size and breast development. Additionally, there is a rise in testosterone during ovulation, when the egg is released during the menstrual cycle.

What Happens if Testosterone is High in Females?

In women, high testosterone can cause oily and acne-prone skin, weight gain, reduction in breast size, mood swings, unwanted hair growth, menstrual irregularities, and infertility. High testosterone in women can be due to Polycystic Ovarian Syndrome (PCOS), tumors in the ovaries, and Cushing's disease.

What Happens if Testosterone is Low in Females?

Symptoms of low testosterone in women include low libido, fatigue, loss of muscle mass, poor concentration, and mood changes. Common causes of low testosterone in women include certain medications like hormonal birth control, early or premature menopause, surgical removal of the ovaries, reduced caloric intake often seen in eating disorders, and other hormonal imbalances and stress.

What Happens if Testosterone is High in Males?

High testosterone in men can negatively impact the cardiovascular (CV) system, including heart muscle damage and increased risk of heart attack, high blood pressure, and high cholesterol. Other symptoms include acne, insomnia, headaches, fluid retention, and mood swings. Liver disease and benign prostatic hyperplasia, an enlargement of the prostate gland causing difficulty urinating, can also be caused by high testosterone.

What Happens if Testosterone is Low in Males?

Symptoms of low testosterone include loss of muscle mass, erectile dysfunction, growth of fatty breast tissue, low libido, infertility, hot flashes, brittle bones, and reduced body and facial hair. Poor focus and memory are also common symptoms. Low testosterone can be due to damage to the testicles, diseases of the pituitary gland, autoimmune conditions, infections, certain medications, obesity, metabolic syndrome, aging, and stress.

How to Test Testosterone Levels

Testosterone can be checked in the blood, saliva, or urine.


Blood testing of testosterone should be done in the morning during the peak release and should be done at the same time in subsequent blood draws. Timing is essential to assess testosterone levels, as testosterone levels can be 30-35% higher in the morning than in the afternoon and evening. The reference range for males is 300 to 1,000 nanograms per deciliter (ng/dL) or 10 to 35 nanomoles per liter (nmol/L), and for females, the range is 15 to 70 ng/dL or 0.5 to 2.4 nmol/L.


Salivary testing, such as the ZRT female/male hormone panel, shows the amount of free testosterone available for immediate use. This can help assess tissue levels of testosterone.


Urine testing, such as the DUTCH test, shows how testosterone is broken down or metabolized. This can give great insight into the enzymes 5alpha-reductase and aromatase, as discussed above.

Functional Medicine Treatment for Testosterone Imbalance


Diet, an important factor for many diseases and conditions, can impact testosterone levels. Low dietary intake of zinc, vitamin D, and magnesium, paired with low polyphenol intake, has been shown to impact the HPG axis. Polyphenols are phytonutrients found in high amounts in berries, herbs and spices, cacao, and nuts.

Lifestyle Changes

Chronic stress has been shown to reduce testosterone production. Adaptogenic herbs, as their name implies, aid in modulating stress hormones. Ashwagandha, Licorice, and Rhodiola are examples of adaptogenic herbs.

Sleep is essential for health. In relation to testosterone, it's thought that testosterone production is highest during sleep and then released at peak levels in the morning. Studies have shown that lack of sleep leads to lower testosterone levels.


Tongkat ali is a botanical traditionally used for men's health, including fertility and sexual functioning. A meta-analysis of nine studies showed Tongkat to improve testosterone levels. The dosage of Tongkat ranged from 100 to 600mg/day for three days to six months.

Zinc plays an important role in testosterone physiology. A systematic review showed zinc deficiency reduces testosterone levels, and zinc supplementation increases testosterone levels.

Fenugreek significantly raises testosterone levels. A meta-analysis of four studies showed that serum testosterone levels increased with fenugreek supplementation.


Testosterone is an essential hormone for both men and women. Testosterone can be viewed as a vital marker for health, affecting sexual function, cognition, bone density, and more. Therefore, testing testosterone levels when indicated may provide insight and provide a pathway to resolving bothersome symptoms.

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