Testosterone Levels by Age: What’s Normal and How They Change Over Time

Understand how testosterone levels change with age, signs of low testosterone, and what you can do to maintain healthy hormone levels.

By Medha deb

Created on Sep 26, 2025

Understand how testosterone levels change with age, signs of low testosterone, and what you can do to maintain healthy hormone levels.

Testosterone, a vital hormone mainly produced in the testes in men and in smaller amounts in the ovaries and adrenal glands in women, has far-reaching effects on health, well-being, and physical development. Understanding how testosterone levels change with age, what symptoms may indicate a problem, and how to address concerns, can support lifelong health and vitality.

Understanding Testosterone: Role and Function

Testosterone plays a crucial role in many bodily functions, especially in men. It influences:

Development of male sex organs during fetal life and at puberty
Secondary sexual characteristics such as facial and body hair, deeper voice, and muscle mass
Libido and sexual function
Bone density and strength
Production of red blood cells
Mood and cognitive performance

How Testosterone Levels Change With Age

Testosterone peaks during adolescence and early adulthood, then gradually declines. After about age 30, levels begin to decrease by about 1-2% per year in men. This is a natural part of aging, though the rate and degree of decline vary between individuals.

Age Range (years)	Normal Total Testosterone Range^* (ng/dL)	Age-Specific Lower Limit (ng/dL)
20–24	409–558	409
25–29	413–575	413
30–34	359–498	359
35–39	352–478	352
40–44	350–473	350

^*Ranges are based on middle tertile values from U.S. population studies and may vary by lab and definition used.

After age 45, published reference ranges generally get broader, but the gradual decline continues for most. Diagnosis of testosterone deficiency should ideally use age-specific reference values.

What Is Low Testosterone?

Low testosterone (also called hypogonadism or “low T”) means the body is not producing enough of the hormone for optimal function. This can happen at any age, though it becomes more common as men get older.

Symptoms of Low Testosterone

The most common signs of low testosterone include:

Reduced sex drive and erectile dysfunction
Low energy or persistent fatigue
Loss of muscle mass and increased body fat
Difficulty concentrating or memory problems
Mood changes, such as depression or irritability
Decreased bone mass or increased risk of fractures
Anemia (reduced red blood cell count)
Loss of facial or body hair

It is important to note that many of these symptoms can overlap with other common health conditions. A blood test is needed to confirm low testosterone levels.

Causes of Low Testosterone Across the Life Span

While aging is the most common cause of declining testosterone, several other factors and medical conditions may contribute:

Testicular injury, trauma, or infection
Genetic conditions (e.g., Klinefelter syndrome)
Disease of the pituitary gland or hypothalamus
Cancer treatments, particularly chemotherapy or radiation therapy
Medications, including opiates and some steroids
Chronic illnesses (such as kidney or liver disease)
Obesity and metabolic disorders, including diabetes
Alcohol misuse or substance abuse
Severe stress

Testosterone Reference Ranges by Age

What is considered a ‘normal’ testosterone level can vary depending on the age group. Clinicians may use age-adjusted reference ranges to better assess what is normal for each individual.

Age Group (years)	Reference Total Testosterone Range (ng/dL)
20–44	~350–575
45–54	~300–550
55–64	~250–500
65+	~200–450

Note: Reference ranges can differ slightly by laboratory and country. Consistent symptoms and low levels confirmed on more than one test are necessary for diagnosis.

Natural Decline and When to Get Tested

Testosterone does not always drop sharply. Some men maintain higher levels late into life, while others experience more pronounced declines. Assessment is typically recommended if you have multiple symptoms of low testosterone, or specific risk factors such as:

History of testicular, pituitary, or hypothalamic disease
History of infertility
Unexplained anemia or bone fractures
Unexplained depression or low sex drive persisting several months

Blood samples are ideally collected in the morning when levels are highest, and repeated for confirmation.

How Is Low Testosterone Diagnosed?

Diagnosis involves a combination of clinical evaluation and blood testing. A typical approach includes:

Review of medical history and symptoms
Physical examination (including body composition, testicular and hair examination)
At least two separate morning total testosterone tests (typically between 7 am and 10 am)
Additional hormone tests or imaging, as needed

Low Testosterone: Potential Health Effects

Persistently low testosterone can have broad consequences for health and well-being, especially in men. Complications may include:

Reduced fertility and lower sperm count
Decreased bone density and increased fracture risk
Increase in body fat and risk of metabolic syndrome
Loss of muscle strength and physical performance
Cognitive decline and mood disorders

Some of these complications may be partly reversible with appropriate treatment, especially if addressed early.

Causes of Low Testosterone in Youth and Women

Although most often discussed in men, low testosterone can affect women and younger people. In females, symptoms are typically subtler but may include reduced libido or difficulties with fertility. Causes in youth may include:

Genetic disorders
Pituitary or hypothalamic dysfunction
Cancer treatments
Chronic illness or malnutrition

Testosterone Replacement Therapy (TRT): Who Should Consider It?

Testosterone replacement therapy (TRT) may be prescribed for men with confirmed low testosterone and clear symptoms. Methods include:

Skin patches worn daily
Topical gels applied to the skin
Mouth tablets that dissolve between gum and cheek
Injections given every few weeks
Implantable pellets that release testosterone slowly

TRT is generally reserved for those with both low blood levels and symptoms. It is not recommended purely for age-related decline unless symptoms are disruptive and other causes have been ruled out. TRT can improve energy, mood, sexual function, bone health, and even red blood cell counts, but regular medical supervision is essential.

Potential Risks and Side Effects of TRT

Acne and oily skin
Breast enlargement or tenderness
Worsening of sleep apnea
High red blood cell counts (polycythemia)
Lower fertility due to suppressed sperm production
Possible increased risk for certain cancers (data still debated)

Doctors weigh the benefits against risks, especially in men with prostate, heart, or liver disease, or a history of blood clots.

Natural Ways to Maintain Healthy Testosterone Levels

Lifestyle and nutrition have a measurable influence on hormone production. Strategies for healthy testosterone levels include:

Regular aerobic and resistance exercise
Weight management, particularly reducing abdominal fat
A balanced diet rich in essential nutrients (proteins, healthy fats, fruits, vegetables, whole grains)
Getting sufficient sleep
Managing chronic stress
Limiting alcohol and avoiding illicit drug use

Diets high in trans fats, uncontrolled diabetes, and excessive body fat are all associated with lower testosterone.

Frequently Asked Questions (FAQs)

What is a normal testosterone level by age?

Normal levels for adult men range from about 350 to 575 ng/dL for those under 45, declining to around 200–450 ng/dL in older men. Individual ranges may vary and depend on lab reference values.

What are the most common symptoms of low testosterone?

Symptoms include reduced sex drive, erectile dysfunction, low energy, loss of muscle and bone mass, mood changes, and difficulty concentrating.

How do I know if I should get my testosterone checked?

If you have multiple symptoms associated with low testosterone or have unexplained physical or mood changes, consult your healthcare provider for evaluation and possible testing.

Can young men or women have low testosterone?

Yes, both young men and women can experience low testosterone due to genetic, hormonal, or medical causes, though symptoms and diagnostic ranges differ.

How is low testosterone treated?

Treatment depends on the cause. In confirmed cases with symptoms, testosterone replacement therapy may be offered. For those with less severe symptoms or at risk due to lifestyle factors, changes such as exercise and diet may help boost levels naturally.

Is it safe to take testosterone supplements or boosters?

Over-the-counter supplements are not regulated for safety and effectiveness. Only take prescribed hormone treatments under medical supervision. Many marketed ‘boosters’ lack strong scientific support.

Key Takeaways

Testosterone levels naturally decline with age, starting around age 30 for most men.
Symptoms of low testosterone can affect sexual, physical, and emotional health.
Testing involves blood work and should be done if symptoms are significant or persistent.
Treatment is individualized, and healthy lifestyle choices can help maintain hormone balance.
TRT is prescribed when both clinical symptoms and low hormone levels are confirmed, under professional guidance.

For individualized advice, always consult your healthcare provider.

References

Author

medha deb

Medha Deb is an editor with a master's degree in Applied Linguistics from the University of Hyderabad. She believes that her qualification has helped her develop a deep understanding of language and its application in various contexts.

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