Why Men Lose Testosterone: The Science

Blog - The role of diet on testosterone

Discovering a decline in testosterone levels can stir up a mix of emotions. It’s a natural progression that accompanies aging, impacting every man to some degree. However, the ramifications can vary widely among individuals. Gaining insight into the scientific underpinnings of this decline sheds light on potential factors influencing your body’s changes and empowers you to explore potential solutions.

What Does Testosterone Do in the Male Body?

Testosterone, an androgenic hormone produced by the testicles, responds to signals from the pituitary gland and hypothalamus. Its significance extends from prenatal development through puberty, contributing to the formation of sex organs and facilitating sperm production.

Beyond reproductive functions, testosterone is instrumental in fostering muscle growth and preserving bone density. It contributes to maintaining a healthy red blood cell count and fosters a general sense of well-being. Additionally, testosterone fuels the emergence of secondary sexual characteristics, including body and facial hair growth, and the deepening of the voice during and after puberty.

What Is Low Testosterone?

Low testosterone occurs when the testicles fail to produce sufficient amounts of testosterone essential for maintaining optimal health. According to guidelines from the American Urology Association, normal testosterone levels range between 300 and 1,000 nanograms per deciliter (ng/dL). Anything falling below the 300 ng/dL threshold is indicative of low testosterone. This condition can lead to a range of significant consequences, including weakened bones, weight gain, sexual dysfunction, and mental health issues.

What Causes Low Testosterone?

Although congenital conditions can predispose some males to low testosterone levels, age-related changes stand as the predominant catalyst. Testosterone production typically commences a natural decline for most men once they reach their 30s. On average, a reduction of approximately 1% per year in testosterone production can be anticipated from the onset of their 40s. Low testosterone may arise from issues affecting either the testicles or the hypothalamus and pituitary gland.

Testicular Disorders

Testicular issues can lead to insufficient testosterone production. Normally, the pituitary gland increases secretion of follicle-stimulating hormone (FSH) and luteinizing hormone (LH) in response to the body’s demand for more testosterone. These hormones prompt the testicles to boost testosterone production. However, damaged testicles may fail to receive or respond to these signals.

Several congenital conditions can contribute to such testicular problems, including undescended testicles, Noonan syndrome, Klinefelter’s syndrome, certain types of muscular dystrophy, and underdevelopment of Leydig cells responsible for testosterone production. Although these conditions are rare, they can impact testosterone levels significantly.

Moreover, testicular damage can result from injury, cancer, chemotherapy, and radiation therapy. Specific types of inflammation, particularly those caused by sexually transmitted diseases or mumps, can also harm the testicles. Additionally, the misuse of anabolic steroids can inflict permanent damage to testicular function.

Disorders of the Pituitary and Hypothalamus

Disorders affecting the pituitary gland and hypothalamus can also lead to testosterone deficiency, often stemming from an impairment in the production of follicle-stimulating hormone (FSH) and luteinizing hormone (LH) by the brain. Rare congenital disorders like Kallmann syndrome and Prader-Willi syndrome can manifest in testosterone deficiency due to these abnormalities.

More commonly, deficiencies in FSH and LH production result from various diseases and conditions affecting the hypothalamus and pituitary gland. These include cirrhosis of the liver, HIV/AIDS, Cushing’s syndrome, or kidney failure. Brain injuries, alcohol use disorder, and obstructive sleep apnea can also impair hormone production. Infections or inflammation of the pituitary gland may disrupt FSH and LH production, while certain medications such as estrogens, opioids, and psychoactive drugs can also have similar effects.

Obesity and Type 2 diabetes are prevalent contributors to dysfunction in the pituitary and hypothalamus, leading to decreased testosterone production. Overweight men are five times more likely to experience low testosterone compared to those with normal weight, while men with Type 2 diabetes face roughly twice the risk.

How Common is Low Testosterone? (And Who Does It Affect?)

The prevalence of low testosterone increases with age, affecting a greater percentage of men as they grow older. While approximately 2% of young men grapple with testosterone deficiency, this figure climbs to around 10% among men in their 50s. Some estimates suggest that up to 30% of older men may experience low testosterone levels.

Notably, testosterone deficiency is more common among older individuals and is often associated with certain health conditions. Men with Type 2 diabetes, obesity, or sleep apnea are at a heightened risk of experiencing low testosterone levels. Furthermore, individuals with chronic medical conditions such as cirrhosis of the liver, kidney dysfunction, or HIV/AIDS are more prone to experiencing declines in testosterone levels.

Why Have Testosterone Levels Been Declining in Recent Years?

While testosterone deficiency is not pervasive among the general male population, there has been a noticeable decline in testosterone levels nationwide over recent decades, independent of age factors. This decline may be emblematic of broader trends in men’s health across the United States, influenced by several contributing factors:

  • Decreased physical activity. Lack of anaerobic exercise, such as weight-lifting, which is known to temporarily elevate testosterone levels, contributes to the decline. Merely engaging in cardio activities may not provide the same testosterone-boosting benefits.
  • Increased alcohol consumption. Excessive alcohol intake, particularly chronic drinking, negatively impacts testosterone levels and can elevate estrogen levels. Metabolizing ethanol and certain endorphins present in alcohol inhibit testosterone production..
  • Exposure to toxins. Exposure to endocrine-disrupting chemicals, commonly found in plastics, poses a concern in modern life. Research exploring the link between these chemicals and testosterone levels is ongoing. Studies indicate that 89% of men seeking treatment for fertility issues show measurable signs of BPA in their bodies, suggesting a potential impact on testosterone levels and reproductive health..
  • Certain diets, especially low-fat diets, have been associated with minor decreases in testosterone levels. Additionally, specific foods such as certain nuts, spearmint, flaxseed, soy, certain fish, and some mushrooms have been linked to decreased testosterone. Meat containing added hormones can also have detrimental effects.
  • Sleep deprivation. Inadequate sleep disrupts normal testosterone production, as testosterone levels are typically highest in the morning. Disruptions in sleep patterns, whether due to obstructive sleep apnea or lifestyle factors, can lead to significant declines in testosterone levels.
  • Increased stress. Elevated stress levels lead to higher cortisol levels, which inhibit the endocrine system, including normal testosterone production.
  • Excess weight. Higher weight and BMI can disrupt the body’s endocrine system, affecting testosterone production and distribution.

 Considering these factors, it’s evident that many aspects of modern life contribute to declining testosterone levels across the population.

The Indicators of Low Testosterone

If you correlate indicators of sexual dysfunction with low testosterone levels, you’re certainly heading in the right direction. However, it’s essential to recognize that testosterone deficiency can manifest in a variety of ways, some of which may not be immediately apparent. Indications of low testosterone encompass:

  • Erectile dysfunction
  • Reduced sperm count and male fertility
  • Cognitive issues such as memory lapses and difficulty concentrating
  • Development of enlarged male breast tissue
  • Decreased stamina and energy levels
  • Loss of bone mass and density, occasionally leading to fractures
  • Persistent fatigue
  • Diminished semen production
  • Fluctuations in mood and increased irritability
  • Decline in libido or sexual desire
  • Thinning or loss of pubic hair
  • Episodes of depression
  • Accumulation of excess body fat
  • Loss of muscle mass
  • Trouble falling or staying asleep

 It’s important to note that not all individuals experiencing testosterone deficiency will encounter every one of these symptoms. Nevertheless, the presence of a combination of the aforementioned indicators without an apparent cause serves as a compelling prompt to consider getting testosterone levels evaluated.

Diagnosing Low Testosterone

The diagnosis of low testosterone levels typically involves a straightforward process of conducting blood tests. Your physician will examine your total testosterone levels to ascertain if they fall below the normal range. Additionally, they may assess LH (luteinizing hormone) and prolactin levels to pinpoint any underlying issues related to the pituitary gland.

Furthermore, a comprehensive physical examination will be conducted by your doctor. This examination will delve into your medical history, encompassing your current medications and any history of smoking. Furthermore, your physician might request a bone density test to gather additional insights.

Is Testosterone Deficiency Treatable?

Indeed, there are numerous avenues available for addressing testosterone deficiency, offering hope for those experiencing its effects. Testosterone replacement therapy stands as the cornerstone of treatment, backed by years of research and several effective delivery methods aimed at elevating testosterone levels and alleviating associated symptoms. These methods encompass: 

  • Testosterone Injections. Administered either at a medical facility or self-administered at home, injections typically provide a sustained testosterone boost for approximately 10 weeks.
  • Testosterone Pellets. Implanted beneath the skin of the upper thigh during a medical visit, these pellets steadily release testosterone over a period of 3 to 6 months, offering a convenient and hassle-free treatment option.
  • Testosterone Gel. Applied daily to the skin of the upper arm, this self-administered method offers ease of use. However, caution must be exercised to prevent inadvertent exposure, particularly to children in the household.
  • Testosterone Patches. Resembling nicotine patches, these patches deliver testosterone through the skin and require daily application, offering a tidy alternative to gel application.


Certain individuals with low testosterone levels may not be suitable candidates for treatment due to underlying health conditions. It’s advised that individuals with a history of prostate cancer or breast cancer avoid testosterone replacement therapy. Additionally, those with uncontrolled obstructive sleep apnea or heart failure may not be considered ideal candidates for this treatment.

For many men, relief from symptoms typically begins within a few weeks of starting treatment. By the 6-month mark, most individuals experience significant alleviation of symptoms, leading to an improved quality of life.

When to Seek Medical Advice for Suspected Low Testosterone

If you notice a decline in your sex drive, encounter erectile dysfunction, observe a loss of muscle mass, or experience other symptoms associated with testosterone deficiency, it’s advisable to consult a doctor for thorough testing and evaluation. However, it’s worth noting that low testosterone levels can sometimes occur without overt symptoms.

We are experts in helping men deal with low testosterone and other endocrine system issues, ensuring they receive the appropriate treatment. If you believe that testosterone replacement therapy could positively impact your life, we encourage you to reach out to us today for personalized assistance.

Call us if you would like to learn more about Testosterone and Hormone Health

To learn more about whether hormone replacement therapy is right for you or to schedule an appointment, contact Texas Testosterone today. We’ll be happy to discuss your needs with you and help you make the best decision for your personal health.