What is Testosterone?

Few men truly understand the nature of testosterone (T), the hormone that is the essence of their manhood. Discussions about testosterone on TV or in advertisements tend to be superficial, misleading, or confusing. Typically they are geared toward one goal: to convince men they need to seek testosterone replacement therapy. In the process, the marketers usually use fear tactics to get their points across. After all, you don’t want to look older or flabbier or be less masculine or less sexy, do you? Then you must need T, yet what should men know about testosterone?

True, men need testosterone throughout their lifetime. Testosterone is essential for the development of male reproductive organs and the promotion of sexual characteristics such as growth of body hair, deepening voice, bone mass, and increased muscle. The hormone also is important after the developmental years to help maintain muscle strength and tone, support sexual prowess and libido, promote red blood cell production, and influence mood.

But like the movie title says, it’s complicated. Testosterone is a complex hormone, and it works with and is influenced by other factors. For example, as men get older, certain undesirable symptoms and body changes begin to develop. Introducing more testosterone into your body most likely is not the answer to resolving any of these symptoms and changes, but that’s not what men are lead to believe.

In fact, numerous factors can have a role in the issues often associated with low testosterone. Once you better understand what testosterone is, what healthy T levels are, and how you can beat those unwanted symptoms without resorting to testosterone therapy, the happier you will be.

So let’s begin our discussion with the different types of testosterone and low testosterone.

What are the types of testosterone?

Testosterone is an androgen produced in males primarily by the testicles. The hormone can be classified into different categories, and they are related to each other in different ways. For example:

Total testosterone is the sum of bioavailable testosterone and testosterone that is bound to a hormone called sex hormone binding globulin (SHBG). Total testosterone is the value often measured when T is tested, but it does not provide you or your doctor with an accurate view of your testosterone status. The value you want to know is free testosterone.

Free testosterone is the form of the hormone that is not bound or attached to binding proteins. This is the active form of the hormone that is available for the body’s use, but it makes up only about 0.3 to 5 percent of the total amount of T in the body. A value of about 2 percent is considered optimum.

Bioavailable testosterone is the sum of free testosterone and T that is attached to the protein called albumin. About 40 percent of the testosterone in the body is bound to albumin. The good thing about this form of testosterone is that albumin can let go of the hormone when the body needs more T.

Sex hormone binding globulin. Another term you should know is sex hormone binding globulin (SHBG). Testosterone that is bound to SHBG is not available to the body. About 60 percent of testosterone is attached to SHBG in young, healthy males. As men age or if they are ill, SHBG becomes more active and attaches itself to more and testosterone, which in turn lowers the amount of free T. The less SHBG a man has, the higher his level of free testosterone.

Therefore, as men get older, they really want to find ways to boost their levels of the bioactive form of testosterone, or free T. This can be done by reducing the activity of SHBG and/or by helping more testosterone break free from albumin.

What is normal and low testosterone?

The range of what is considered to be a “normal” testosterone level is wide and depends largely on age. For example, the normal or healthy range for men age 20 to 39 years is about 270 to 1,080 ng/dL (nanograms of T per deciliter of blood); for men 40 to 59, 350 to 890 ng/dL; and for men 60 and older, 350 to 720 ng/dL.

The professional definition of clinical testosterone deficiency is a value less than 200 ng/dL. Men who have testosterone levels in this very low range are usually diagnosed as having hypogonadism (testosterone deficiency), in which the body is not making enough of the hormone. In such cases, the treatment is testosterone replacement therapy. In fact, hypogonadism is the only condition for which testosterone should truly be prescribed.

However, men and their healthcare providers often turn to testosterone (which is available by prescription) based solely on symptoms typically attributed to low T (see below) without undergoing a blood test to identify T levels. The symptoms associated with low testosterone levels are as follows:

  • Little or no sex drive
  • Erectile dysfunction
  • Loss of lean muscle mass
  • Low energy or fatigue
  • Increase in belly fat
  • Problems with memory, concentration, and attention span
  • Reduced strength
  • Depressed mood

Some men also experience breast enlargement, bone loss, and problems with urination. As you can see, the symptoms of low T are a pretty depressing lot. So when the fear mongers tell you that taking testosterone could resolve them, who wouldn’t want to believe it?

What causes testosterone to decline

Many factors can cause testosterone levels to decline, and age is usually targeted as the main culprit. T levels naturally decrease by about 1 percent per year starting at age 30.

However, other factors also contribute to testosterone decline, including diabetes, obesity, poor diet, lack of sleep, exposure to environmental pollutants (e.g., phthalates, pesticides, fungicides, BPA), use of certain medications, stress, alcohol consumption, and presence of chronic illness, such as liver or kidney disease. Notice that nearly all of these factors have one thing in common: they are preventable or can be managed effectively, which means men can take action to keep their testosterone levels at a healthful level regardless of age.

This idea is supported by research. A study in the Journal of Clinical Endocrinology and Metabolism, for example, pointed out that “poor health may accelerate the age-related decline” in testosterone and other male hormone levels. In a more recent report that involved men in the Healthy Man Study in Australia, the authors evaluated blood samples from 325 men to identify testosterone levels over a three-month period. They concluded that “age alone does not make you testosterone deficient.”

How do you boost free testosterone?

No matter how old you are, you can take steps right now to boost your levels of free testosterone. The following suggestions, along with the subsequent tips on how to maintain healthy T levels as you age, can help you avoid or better live with any symptoms typically associated with low testosterone. Because unless you have a diagnosis of hypogonadism, you don’t need a prescription for testosterone. You need to make lifestyle changes.

  • Boron. This dietary trace mineral improved free testosterone levels in a group of healthy men. A dose of 10 mg taken daily for one week resulted in a significant decline in SHGB and a significant rise in free testosterone. The study was noted to be “the first human study report to show an increase level of free testosterone after boron consumption.”
  • Exercise. The good news is that intense but short-term exercise done on a regular basis, several times a day, can boost your T levels while prolonged endurance exercise may lower them. Moderate exercise can be good too. For example, 45 minutes of moderate activity resulted in a nearly 40 percent rise in free T as reported in an International Journal of Sports Medicine
  • Reduce estrogen. In men, estrogen (in the form of estradiol) is produced from testosterone and other androgens, and production can rise as men get older. To reduce estrogen production, avoid or eliminate exposure to estrogen-mimicking chemicals (xenoestrogens). These are found in the lining of food cans (bisphenol A [BPA]), plastic food and beverage containers, pesticides, hormones in meats, and personal care products, among others. Choosing organic foods, managing stress, and maintaining a healthy weight also can help reduce estrogen levels.
  • Stinging nettle. This herb (Urtica dioica) reportedly can disrupt the ability of SHBG, which in turn can result in higher levels of free testosterone.
  • Tongkat ali. The root of this tree (Eurycoma longifolia) has been shown to boost testosterone levels. In a 2014 study, a group of older physically active men took 400 mg of tongkat ali extract daily for five weeks. Use of the herbal remedy was associated with a significant increase in both total and free T concentrations by the end of the trial. The men also experienced an increase in muscle strength.

How can I naturallyincrease my testosterone levels?

All men also can take other steps to support and maintain healthy testosterone levels. These lifestyle choices include the following. Start today!

  • Diet. Certain foods are especially testosterone friendly. For example, foods rich in zinc and vitamin D3 can support and maintain testosterone levels. Oysters, fatty fish, organic meats (limited amounts), beans, and nuts should be part of a diet that includes lots of fresh fruits and vegetables, which are rich sources of vitamins, minerals, and phytonutrients that are important for testosterone production. Fruits rich in vitamin C, for example, help lower cortisol, the stress hormone, and low cortisol is associated with higher T levels.
  • Exercise. Regular exercise that includes aerobic movement plus strength training several times a week is recommended.
  • Limit or avoid alcohol. Excess alcohol consumption can lower T levels.
  • Get sufficient amount of sleep. Sleeping less than 7 to 8 hours a night can cause your testosterone levels to decline.
  • Limit or avoid exposure to environmental pollutants. Sure, environmental toxins are everywhere, but you can take significant steps by choosing only organically grown foods, avoiding BPA and phthalates in food packaging and plastic food and beverage containers, using only natural insect and pest control products, and choosing natural personal care products.
  • Lose weight/maintain a healthy weight. Excess fat cells produce estrogen, which throws a monkey wrench into your testosterone:estrogen balance. If you lose fat while building muscle (through exercise), you can restore your hormone balance and maintain T levels.
  • Ask your doctor about your medications. Some drugs can contribute to lower testosterone levels, including certain antidepressants, cimetidine, chemotherapy drugs, ketoconazole, spironolactone, opioids, and statins.
  • Practice stress management. Chronic stress raises levels of the stress hormone, cortisol, which in turn disrupts production of testosterone. Make stress management practices (e.g., meditation, tai chi, yoga, progressive relaxation) a part of your daily routine.
  • Consider natural supplements. Vitamin D supplements are frequently recommended because many men have low levels of this nutrient and it can be a challenge to get enough through food. You can also try natural supplements that boost testosterone levels.

The ability to support, promote, and maintain healthy levels of testosterone and to effectively manage or avoid symptoms typically associated with low T does not lie in a prescription for testosterone. It lies with you. Healthy lifestyle choices can be your road to better sexual stamina, improved muscle strength, a robust libido, and a more positive mood.

Read more in our Low T Health Center.

References

Fahrner CL, Hackney AC. Effects of endurance exercise on free testosterone concentration and the binding affinity of sex hormone binding globulin (SHBG). International Journal of Sports Medicine 1998 Jan; 19(1): 12-15

Henkel RR et al. Tongkat ali as a potential herbal supplement for physically active male and female seniors—a pilot study. Phytotherapy Research 2014 Apr; 28(4): 544-50

Naghii MR et al. Comparative effects of daily and weekly boron supplementation on plasma steroid hormones and proinflammatory cytokines. Journal of Trace Elements in Medicine and Biology 2011 Jan; 25(1): 54-58