Testosterone Replacement Therapy

Testosterone is one of the most important hormones in the human body — and contrary to popular belief, it is essential for both men and women. In men, testosterone is the primary androgen, responsible for muscle development, bone density, red blood cell production, fat distribution, libido, sperm production, and a host of cognitive and emotional functions. In women, testosterone plays equally critical roles in maintaining energy, sexual desire, muscle tone, bone strength, and mental clarity, though at significantly lower circulating levels.

Testosterone production follows a predictable pattern of decline with age. In men, testosterone levels peak in the late teens to early twenties and begin decreasing at a rate of approximately 1-2% per year after age 30. By age 50, many men have lost 30-50% of their peak testosterone production. By age 70, levels may have fallen to a fraction of their youthful baseline. This gradual decline is sometimes called andropause, late-onset hypogonadism, or colloquially "male menopause."

In women, testosterone levels peak in the early twenties and decline steadily throughout the reproductive years. By the time a woman reaches menopause, her testosterone levels may be only 50% of what they were at age 20. Women who undergo surgical menopause (removal of the ovaries) experience an even more dramatic drop, as the ovaries are a primary source of female testosterone production.

The insidious nature of testosterone decline is that it occurs so gradually that many people fail to recognize it. They attribute their fatigue to a busy lifestyle, their weight gain to a slowing metabolism, their diminished motivation to stress, and their reduced libido to the natural consequence of aging. In reality, these symptoms often have a single underlying cause — low testosterone — and they are highly treatable with properly administered testosterone replacement therapy.

Low testosterone in men produces a constellation of symptoms that affect physical health, mental function, emotional well-being, and sexual performance. The severity of symptoms varies based on how far testosterone levels have fallen below the optimal range and how long the deficiency has persisted.

Physical symptoms are often the most visible. Men with low testosterone typically experience progressive loss of lean muscle mass, even when maintaining their exercise routine. Simultaneously, body fat increases, particularly in the abdominal area, creating the classic "middle-age spread" that many men simply accept as inevitable. Strength and endurance decline, recovery from physical activity takes longer, and the overall sense of physical capability diminishes.

Cognitive and emotional symptoms can be equally debilitating. Testosterone has direct effects on brain function, influencing neurotransmitter production, neural connectivity, and cognitive processing speed. Men with low testosterone frequently report brain fog, difficulty concentrating, impaired memory, reduced mental sharpness, and a pervasive sense of mental sluggishness. Emotionally, low testosterone is associated with irritability, mood swings, reduced motivation, feelings of apathy, and in many cases, clinical depression.

Sexual health is profoundly affected by testosterone deficiency. Reduced libido — a diminished desire for sexual activity — is one of the hallmark symptoms of low testosterone. Erectile function may also be compromised, with men experiencing less firm erections, difficulty maintaining erections, or reduced sexual stamina. Morning erections, which are a reliable indicator of testosterone status, become less frequent or disappear entirely.

Other symptoms include chronic fatigue that is not relieved by rest, disrupted sleep (including insomnia and reduced sleep quality), decreased bone density, joint pain, hair thinning, and a general sense of diminished vitality. Many men describe the experience as feeling like they have aged 20 years in the span of five — a feeling that testosterone replacement therapy can effectively reverse.

While testosterone is often thought of as exclusively a "male" hormone, this misconception has left millions of women suffering from treatable testosterone deficiency without ever receiving a proper diagnosis. Women produce testosterone in their ovaries and adrenal glands, and although female testosterone levels are roughly one-tenth of male levels, the hormone is no less important for women's health and well-being.

Testosterone in women supports muscle tone and physical strength, bone mineral density, energy and stamina, mental clarity and cognitive function, mood stability, and — critically — sexual desire and arousal. When testosterone levels decline, women experience symptoms that are frequently misdiagnosed as depression, chronic fatigue syndrome, fibromyalgia, or simply the "normal" effects of aging.

The most common symptoms of low testosterone in women include persistent fatigue that does not improve with rest, loss of muscle tone despite regular exercise, decreased libido and difficulty achieving arousal or orgasm, brain fog and impaired concentration, mood flatness or low-grade depression, reduced motivation and drive, weight gain (particularly around the midsection), and thinning hair. Many women also report a general loss of their sense of well-being — a feeling that something is "off" even though they cannot identify exactly what has changed.

Dr. Riegel is one of a relatively small number of physicians who fully understands and treats testosterone deficiency in women. His career-long focus on hormone medicine — beginning with four years of hormone research at UT Southwestern Medical School — gives him a depth of knowledge about female hormonal physiology that most hormone clinics simply do not possess. He recognizes that optimal female health requires balanced levels of all hormones, including testosterone, and his treatment protocols are specifically designed to address the unique hormonal needs of women.

Women under Dr. Riegel's care who receive appropriate testosterone supplementation as part of a comprehensive bioidentical hormone protocol consistently report improvements in energy, mental clarity, sexual desire, mood, and body composition that they did not think were possible. For many, it is the missing piece that makes their overall hormone therapy truly effective.

Low testosterone can result from a variety of factors, and understanding the underlying cause is essential for effective treatment. The most common cause is the natural age-related decline in testosterone production, but numerous other factors can accelerate or exacerbate this decline.

Aging remains the primary driver. The testes in men and the ovaries and adrenal glands in women gradually produce less testosterone over time due to cellular aging of the hormone-producing tissues. This process is influenced by genetics, and some individuals experience more rapid decline than others. Certain medical conditions can further suppress testosterone production, including obesity (fat tissue contains aromatase, an enzyme that converts testosterone to estrogen), type 2 diabetes, metabolic syndrome, chronic stress (elevated cortisol suppresses testosterone), sleep disorders (testosterone is primarily produced during deep sleep), pituitary gland disorders, and testicular or ovarian dysfunction.

Medications can also contribute to low testosterone. Opioid pain medications, corticosteroids, certain antidepressants, and statins have all been associated with reduced testosterone levels. Chemotherapy and radiation therapy for cancer can damage hormone-producing tissues, sometimes permanently. Surgical interventions, including hysterectomy, oophorectomy, and orchiectomy, directly eliminate sources of testosterone production.

Lifestyle factors play a significant role as well. Chronic stress elevates cortisol, which directly inhibits testosterone production through the hypothalamic-pituitary-gonadal axis. Excessive alcohol consumption suppresses testosterone synthesis and increases its conversion to estrogen. Inadequate sleep — both in duration and quality — disrupts the nocturnal testosterone production cycle. Sedentary behavior, poor nutrition, and exposure to endocrine-disrupting chemicals in plastics, pesticides, and personal care products can all contribute to testosterone decline.

Dr. Riegel's comprehensive evaluation identifies not just the fact of low testosterone but also the contributing factors that may be accelerating your decline. This allows him to develop a treatment strategy that addresses root causes while simultaneously restoring your testosterone levels to the optimal range through bioidentical hormone therapy.

Dr. Riegel's approach to testosterone replacement therapy reflects over three decades of specialized experience in hormonal medicine. As a board-certified OB/GYN who has focused on hormones his entire career, he brings a level of expertise to testosterone therapy that sets The Riegel Center apart from the proliferation of testosterone clinics that have emerged in recent years.

The foundation of Dr. Riegel's approach is comprehensive testing. Rather than relying on a single total testosterone measurement — which is all many clinics perform — Dr. Riegel orders a complete hormonal profile that includes total testosterone, free testosterone, sex hormone-binding globulin (SHBG), estradiol, DHEA-S, cortisol, thyroid panel, complete blood count, metabolic panel, and other relevant biomarkers. This thorough assessment is critical because testosterone does not function in isolation. Its effectiveness depends on its ratio to estradiol, its binding to SHBG, the adequacy of DHEA as a precursor hormone, thyroid function, and numerous other interrelated factors.

Based on this comprehensive data, Dr. Riegel designs a customized bioidentical testosterone protocol tailored to your specific physiology. He uses exclusively bioidentical testosterone — molecularly identical to the testosterone your body produces naturally — because it provides the most predictable, natural response with the fewest side effects. His proprietary formulations are carefully calibrated to achieve optimal levels without exceeding physiological boundaries.

Dr. Riegel also addresses the common pitfalls that plague testosterone therapy at less specialized clinics. For example, testosterone can be converted to estradiol by the aromatase enzyme, particularly in patients with excess body fat. If this conversion is not monitored and managed, men can develop symptoms of estrogen excess — including water retention, breast tissue enlargement, and mood disturbances — even while their testosterone levels appear adequate. Dr. Riegel proactively monitors and manages aromatization to ensure that your testosterone therapy produces the intended benefits without unwanted estrogenic effects.

For women, Dr. Riegel's dosing is precisely calibrated to the female physiological range. Women need much smaller doses of testosterone than men, and the margin between therapeutic and excessive levels is narrower. His expertise in female endocrinology ensures that women receive enough testosterone to experience meaningful benefits without developing androgenic side effects such as acne, facial hair growth, or voice changes.

Restoring testosterone to optimal physiological levels produces benefits that extend across virtually every dimension of health. Patients under Dr. Riegel's care consistently report dramatic improvements that transform their daily experience of life.

Energy and vitality are among the first benefits patients notice. Within weeks of beginning testosterone therapy, the crushing fatigue that has characterized their days begins to lift. Patients describe waking up refreshed, maintaining consistent energy throughout the day, and no longer needing to push through a wall of exhaustion to accomplish basic tasks. This restoration of energy is not a stimulant-like boost — it is the return of natural, sustainable vitality that comes from a body functioning as it was designed to.

Body composition improvements follow as testosterone levels optimize. Lean muscle mass increases, making it easier to build and maintain muscle through exercise. Simultaneously, body fat — particularly the visceral abdominal fat that is most dangerous to metabolic health — begins to decrease. Many patients who have struggled unsuccessfully with weight management for years find that optimized testosterone finally allows them to make meaningful progress.

Cognitive function sharpens noticeably. The brain fog, poor concentration, and memory lapses that accompanied low testosterone give way to clearer thinking, faster mental processing, and improved recall. Patients frequently describe this cognitive improvement as one of the most impactful benefits of treatment — they feel mentally sharp and capable in ways they had forgotten were possible.

Mood and emotional well-being stabilize as testosterone reaches optimal levels. The irritability, apathy, and depression associated with low testosterone are replaced by a more positive, motivated, and emotionally balanced state. Many patients report that they feel like themselves again — that the person they remember being before hormonal decline has returned.

Sexual health is restored comprehensively. Libido returns, arousal improves, sexual performance is enhanced, and the overall satisfaction derived from intimate relationships increases significantly. For both men and women, this restoration of sexual vitality has profound implications for relationship quality, self-confidence, and overall life satisfaction.

Bone density, cardiovascular health markers, and metabolic function also improve with optimized testosterone levels, providing long-term health benefits that extend well beyond symptom relief.

Effective testosterone replacement therapy requires ongoing monitoring and expert management. At The Riegel Center, Dr. Riegel has developed a monitoring protocol that ensures your treatment remains safe, effective, and optimally calibrated throughout your time under his care.

Follow-up laboratory testing is performed at regular intervals after you begin therapy. The first follow-up typically occurs four to six weeks after starting treatment, allowing enough time for your body to reach steady-state hormone levels. Subsequent testing is scheduled based on your individual response and stability. Dr. Riegel tracks not only your testosterone levels (total and free) but also estradiol, SHBG, hematocrit, hemoglobin, PSA (for men), liver function, lipid panel, and other relevant markers.

Hematocrit monitoring is particularly important in testosterone therapy for men. Testosterone stimulates red blood cell production (erythropoiesis), and in some men, this can cause hematocrit levels to rise above the normal range — a condition called polycythemia that increases blood viscosity and cardiovascular risk. Dr. Riegel proactively monitors hematocrit and adjusts treatment if needed to keep levels within safe parameters.

For men, PSA (prostate-specific antigen) monitoring is included as a standard part of ongoing care. While testosterone replacement therapy does not cause prostate cancer — a myth that has been thoroughly debunked by modern research — Dr. Riegel monitors PSA as a general health measure and to identify any prostate issues that may develop independently of testosterone therapy.

Dosage adjustments are made based on the combined evidence of your laboratory results and your subjective experience. Achieving optimal hormone levels is not a one-time event but an ongoing process of refinement. Factors such as changes in body weight, stress levels, sleep quality, exercise habits, and other medications can all influence how your body metabolizes testosterone, and your protocol may need periodic adjustment to maintain optimal results. Dr. Riegel's attentive monitoring ensures that these adjustments are made proactively, keeping you at your best at all times.