Low Testosterone in Men: More than Just a Number

When most people hear the word testosterone, they immediately think about sex drive or muscle mass. However, testosterone affects much more than sexual performance.

Testosterone supports a man’s energy, motivation, mood, muscle strength, bone health, body composition, red-blood-cell production, sexual function, and overall sense of well-being. When testosterone levels decline, the symptoms can affect nearly every part of daily life.

Some men know that something has changed long before a laboratory report officially labels their testosterone as “low.” They may feel exhausted, unmotivated, mentally foggy, weaker, or less interested in intimacy—yet be told that their result is still within the laboratory’s reference range.

That is why testosterone should not be evaluated by looking at one number alone.

What Is Testosterone?

Testosterone is the primary male sex hormone. It is produced mainly by the testicles, with a small amount also produced by the adrenal glands.

Production is controlled through communication between the brain and the testicles:

1. The hypothalamus in the brain releases a signal called gonadotropin-releasing hormone.

2. The pituitary gland responds by releasing luteinizing hormone, or LH, and follicle-stimulating hormone, or FSH.

3. LH signals the testicles to produce testosterone.

4. FSH and testosterone help support sperm production.

This communication system is known as the hypothalamic-pituitary-gonadal axis.

A problem involving the testicles, pituitary gland, hypothalamus, medications, chronic disease, obesity, sleep, or other factors may reduce testosterone production.

What Does Testosterone Do in the Male Body?

Testosterone plays an important role from fetal development through adulthood.

Sexual development

During puberty, testosterone contributes to:

• Growth of the penis and testicles

• Deepening of the voice

• Facial and body-hair development

• Increased muscle mass

• Male-pattern fat distribution

• Sexual maturation

Sexual desire and function

Testosterone helps support:

• Sexual desire, or libido

• Sexual thoughts and interest

• Spontaneous and morning erections

• Erectile function

• Orgasm and sexual satisfaction

Testosterone is not the only factor involved in erections. Blood flow, nerve function, diabetes, cardiovascular health, stress, medications, sleep, relationship concerns, and psychological health can also affect sexual performance.

However, reduced libido and fewer spontaneous or morning erections are among the symptoms more closely associated with testosterone deficiency.

Muscle mass and strength

Testosterone supports protein production within muscle tissue. Healthy testosterone levels help men maintain:

• Lean muscle mass

• Physical strength

• Exercise capacity

• Recovery

• Functional independence as they age

When testosterone is low, a man may notice declining strength, reduced exercise performance, or loss of muscle despite continuing his usual routine.

Bone health

Testosterone helps maintain bone formation and density. Some testosterone is also converted into estradiol, which is important for male bone health.

Persistently low testosterone may contribute to:

• Osteopenia

• Osteoporosis

• Loss of height

• Increased fracture risk

Low testosterone may not cause obvious bone symptoms until significant bone loss or a fracture has already occurred.

Red-blood-cell production

Testosterone helps stimulate red-blood-cell production.

Testosterone deficiency may contribute to anemia in some men, which can worsen fatigue, weakness, exercise intolerance, and shortness of breath.

However, testosterone treatment can sometimes increase red-blood-cell production too much. This is why hemoglobin and hematocrit must be monitored during treatment.

Mood, motivation, and mental well-being

Testosterone interacts with the brain and may influence:

• Motivation

• Confidence

• Mood

• Mental energy

• Concentration

• Sense of well-being

Some men with low testosterone describe feeling emotionally flat, less driven, more irritable, or unlike themselves.

Depression, anxiety, poor sleep, medications, chronic stress, thyroid disease, and other medical conditions can produce similar symptoms, so a complete evaluation remains important.

Metabolism and body composition

Testosterone helps influence how the body maintains muscle and stores fat.

When testosterone is low, some men may experience:

• Loss of lean muscle

• Increased abdominal or body fat

• Reduced strength

• Lower exercise tolerance

• Difficulty improving body composition

Testosterone treatment is not a weight-loss medication, and difficulty losing weight does not automatically mean a man has low testosterone. Nutrition, activity level, insulin resistance, sleep, medications, thyroid function, stress, and age must also be considered.

Fertility

Testosterone is essential for normal sperm production—but prescription testosterone can actually reduce fertility.

When testosterone is supplied from outside the body, the brain may reduce LH and FSH signaling to the testicles. This can decrease sperm production and cause testicular shrinkage.

Men who currently want children or may want children in the future must discuss this before beginning testosterone therapy. Other treatment approaches may sometimes be considered when preserving fertility is a priority.

What Are the Symptoms of Low Testosterone?

Symptoms vary considerably from one man to another. They may develop gradually and can easily be blamed on aging, stress, overwork, or lack of sleep.

Possible symptoms include:

• Decreased sexual desire

• Fewer sexual thoughts

• Fewer morning or spontaneous erections

• Erectile difficulties

• Reduced sexual satisfaction

• Fatigue

• Reduced stamina

• Loss of motivation or drive

• Depressed or low mood

• Increased irritability

• Difficulty concentrating

• Brain fog

• Reduced muscle mass

• Loss of strength

• Increased body fat

• Reduced exercise performance

• Longer recovery after physical activity

• Decreased facial or body-hair growth

• Breast tenderness or enlargement

• Smaller testicular size

• Hot flashes in cases of severe deficiency

• Reduced bone density

• Infertility

• Unexplained anemia

Low sexual desire, fatigue, reduced lean muscle mass, irritability, erectile dysfunction, and depression are recognized symptoms associated with testosterone deficiency. However, these symptoms are not unique to low testosterone and may have several possible causes.

Why Can Testosterone Decline?

Testosterone levels may gradually decrease with age, but age is not the only reason a man may develop low testosterone.

Possible contributors include:

• Testicular injury or infection

• Previous testicular surgery

• Chemotherapy or radiation

• Genetic conditions

• Pituitary or hypothalamic disorders

• Elevated prolactin

• Obesity

• Type 2 diabetes

• Untreated sleep apnea

• Chronic kidney or liver disease

• Severe or prolonged illness

• Significant calorie restriction

• Opioid medication use

• Glucocorticoid medication use

• Anabolic-steroid use or withdrawal

• Heavy alcohol use

• Certain medications

• Poor or insufficient sleep

Some causes may be reversible or improved by treating the underlying condition. That is why testosterone should not simply be prescribed without investigating why the level is low.

Why Is Testosterone Testing More Complicated Than One Number?

Testosterone levels naturally vary throughout the day. They are generally highest in the morning and may fall later in the day.

Levels may also be temporarily reduced by:

• Poor sleep

• Acute illness

• Severe stress

• Fasting or undernutrition

• Recent intense exercise

• Certain medications

• Laboratory differences

For this reason, major guidelines recommend confirming suspected testosterone deficiency with at least two separate early-morning testosterone measurements rather than relying on one isolated result. A diagnosis should include both consistent symptoms or signs and repeatedly low testosterone levels.

What Is Considered a Low Testosterone Level?

The American Urological Association uses a total testosterone level below 300 ng/dL as a reasonable cutoff supporting a diagnosis of testosterone deficiency. However, the diagnosis should not be made from that number alone. Symptoms and repeat testing are also required.

Other organizations, laboratories, insurance companies, and medication policies may use somewhat different criteria.

This creates understandable frustration. A man may have significant symptoms and a testosterone result slightly above an insurer’s treatment cutoff. He may then be told that his level is “normal,” even though he feels very different from his previous baseline.

Can a Man Have Symptoms When His Testosterone Is Technically “Normal”?

Yes, a man may experience symptoms while his result falls within a broad laboratory reference range.

However, this does not automatically prove that testosterone is the cause.

A laboratory range is designed to describe results seen within a population. It does not measure:

• What the man’s testosterone level was earlier in adulthood

• How much his level has changed over time

• How much testosterone is biologically available

• Whether his test was collected at the correct time

• Whether an illness or medication temporarily lowered the result

• How sensitive his tissues are to hormonal changes

• Whether another condition is causing the same symptoms

A result should therefore be interpreted in context rather than dismissed simply because it is not marked with a red flag.

At the same time, treating every symptomatic man whose result falls within the reference range is not supported by current guidelines. A careful evaluation is needed to determine whether testosterone deficiency, another health condition, or a combination of factors is contributing to his symptoms.

Total Testosterone Versus Free Testosterone

Most testosterone in the bloodstream is attached to proteins.

The major binding proteins include:

• Sex hormone-binding globulin, or SHBG

• Albumin

Only a small portion circulates as free testosterone, meaning it is not bound to a protein.

Total testosterone measures both bound and unbound testosterone. Free testosterone estimates the portion that is immediately available to tissues.

A man may have a total testosterone result that appears acceptable but have lower available testosterone because of an elevated SHBG level. Conversely, a man with low SHBG may have a lower total testosterone while maintaining a more adequate free testosterone level.

SHBG can be affected by:

• Age

• Obesity

• Insulin resistance

• Thyroid conditions

• Liver disease

• Certain medications

• Changes in estrogen levels

• Other medical conditions

When total testosterone is near the lower limit or does not match the clinical picture, evaluating SHBG and a reliable free or calculated free testosterone may provide additional information. The Endocrine Society recommends considering free testosterone when indicated rather than relying exclusively on total testosterone.

Why Might Insurance Deny Treatment?

Insurance coverage policies are administrative rules. They may require:

• Specific symptoms

• Two low morning testosterone results

• A total testosterone below a designated cutoff

• Documentation of an underlying cause

• Additional testing

• Prior authorization

• Use of a preferred medication

• Proof that certain contraindications have been considered

These requirements do not necessarily capture every detail of an individual man’s experience.

However, insurance standards are usually based partly on FDA-approved indications and professional guidelines. FDA-approved testosterone products are indicated for men with low testosterone associated with specific medical disorders affecting testosterone production. FDA labeling retains a limitation of use for testosterone decline attributed only to aging.

A denial of coverage does not by itself prove that treatment is medically inappropriate. It means the insurer’s specific coverage criteria have not been met. The clinical decision and the insurance decision are related, but they are not always identical.

What Should a Complete Low-Testosterone Evaluation Include?

A thoughtful evaluation may include:

• A detailed symptom history

• Sexual and reproductive history

• Medication and supplement review

• Sleep assessment

• Review of alcohol or substance use

• Physical examination when appropriate

• At least two properly timed morning total testosterone measurements

• Free testosterone or SHBG when indicated

• LH and FSH

• Prolactin in selected patients

• Complete blood count

• Metabolic testing

• Thyroid testing when appropriate

• Evaluation for diabetes or insulin resistance

• Prostate-related assessment based on age and risk

• Investigation for pituitary disease when indicated

• Discussion of current and future fertility goals

LH and FSH can help determine whether the problem originates primarily in the testicles or in the pituitary and hypothalamus.

Very low testosterone, abnormal prolactin, headaches, visual changes, or unexpectedly low pituitary hormones may require additional evaluation.

Can Testosterone Therapy Help?

For appropriately selected men with confirmed testosterone deficiency, treatment may improve certain symptoms.

Potential benefits may include improvements in:

• Sexual desire

• Spontaneous erections

• Sexual function

• Lean muscle mass

• Strength

• Bone density

• Anemia

• Mood or sense of well-being in some men

Not every symptom improves, and results vary. Fatigue, weight concerns, depression, and erectile dysfunction frequently have more than one cause.

Testosterone therapy should be viewed as one part of a comprehensive treatment plan not a substitute for sleep, nutrition, resistance training, cardiovascular risk management, diabetes care, mental-health care, or treatment of other medical conditions.

What Are the Risks of Testosterone Therapy?

Possible side effects and risks include:

• Increased hematocrit or excessive red-blood-cell production

• Acne or oily skin

• Fluid retention

• Increased blood pressure

• Breast tenderness or enlargement

• Worsening of untreated sleep apnea

• Reduced sperm production

• Infertility

• Testicular shrinkage

• Changes in urinary or prostate symptoms

• Transfer of topical testosterone to a partner or child

  
  

In 2025, the FDA removed the class-wide boxed-warning language about increased cardiovascular risk after reviewing results from the TRAVERSE trial. At the same time, the FDA required testosterone-product labeling to include warnings about increased blood pressure and retained limitations concerning age-related testosterone decline.

Treatment still requires individualized cardiovascular assessment and ongoing monitoring.

Who May Not Be a Candidate?

Testosterone therapy may not be appropriate or may need to be postponed or coordinated with a specialist for men with:

• A current desire to conceive

• Known or suspected prostate cancer

• Known or suspected male breast cancer

• Significantly elevated hematocrit

• Untreated severe sleep apnea

• Uncontrolled heart failure

• Recent major cardiovascular events

• Severe uncontrolled urinary symptoms

• An unexplained elevated PSA

• Other significant medical concerns

A history of cardiovascular disease or prostate concerns does not always lead to the same decision for every man. It requires careful assessment, discussion, and monitoring.

How Is Testosterone Therapy Monitored?

Monitoring may include:

• Symptom response

• Total and sometimes free testosterone

• Complete blood count and hematocrit

• Blood pressure

• PSA and prostate-related assessment when appropriate

• Side effects

• Sleep-apnea symptoms

• Cardiovascular health

• Fertility concerns

• Medication adherence and administration technique

Treatment should have clear goals. If testosterone levels improve but the original symptoms do not, the plan should be reassessed rather than increasing the dose indefinitely.

The goal is not to create the highest possible testosterone level. The goal is to restore an appropriate, stable level that improves clinically relevant symptoms without causing harm.

Men Deserve More Than “Your Number Is Normal”

Men should not have their symptoms ignored simply because one testosterone result falls slightly above an insurance or laboratory cutoff.

They also deserve more than an automatic prescription.

The appropriate approach is to listen carefully, repeat testing correctly, consider total and free testosterone when indicated, identify possible causes, evaluate competing explanations, discuss fertility, and weigh the potential benefits and risks of treatment.

At Holistic Wellness 4U, we evaluate the entire clinical picture—not one isolated number. We review symptoms, correctly timed laboratory results, health history, medications, sleep, metabolic health, fertility goals, and other possible causes before deciding whether testosterone therapy may be appropriate.

Are you experiencing fatigue, declining strength, low motivation, reduced sexual desire, or other symptoms that may be related to low testosterone? Schedule a consultation with Holistic Wellness 4U for a comprehensive and individualized evaluation.

This information is provided for educational purposes only and is not a substitute for individualized medical advice, diagnosis, or treatment. Testosterone is a prescription medication and controlled substance. It should only be prescribed after an appropriate evaluation and monitored by a qualified healthcare professional.