For adult men, a normal total testosterone range is typically 300 to 1000 nanograms per deciliter (ng/dL), though lab reference ranges vary. Levels naturally decline with age, with average testosterone dropping about 1 percent per year after age 30. Free testosterone, the fraction your body can actually use, is often more important for assessing health and symptoms.

Key Takeaways

  • Total testosterone normal range is generally 300 to 1000 ng/dL for adult men, with some variation by laboratory.
  • Testosterone declines with age, approximately 1 percent per year after age 30, but many older men remain within normal limits.
  • Free testosterone and clinical symptoms are more meaningful for evaluating low testosterone than total testosterone alone.
  • Levels consistently below 300 ng/dL combined with symptoms may indicate hypogonadism requiring medical evaluation.
  • Testing should be done in the morning, ideally between 7 and 10 a.m., when levels peak.

What Is the Normal Testosterone Range for Men by Age?

Normal testosterone levels vary by age, with younger men typically having higher levels and older men lower levels, but a common reference range is 300 to 1000 ng/dL for total testosterone. However, no single number applies perfectly to every man. Laboratories set their own reference intervals based on healthy populations, so you may see slight differences between reports.

For men in their 20s and 30s, total testosterone often falls between 400 and 1000 ng/dL. By age 40 to 50, average levels may decline to around 300 to 800 ng/dL. After age 60, some men maintain levels above 300 ng/dL, while others dip below that threshold. Importantly, free testosterone declines more steeply with age because a protein called sex hormone binding globulin (SHBG) increases, binding more testosterone and making less available.

Many experts consider a total testosterone level below 300 ng/dL on two separate morning tests, along with symptoms such as low libido or fatigue, as criteria for low testosterone or hypogonadism. But older men with levels in the 200 to 300 ng/dL range may not need treatment if they have no symptoms.

How Do Doctors Measure Testosterone and What Types Matter?

Doctors typically measure total testosterone first, but free testosterone and bioavailable testosterone are often more useful for assessing symptoms. Total testosterone includes both bound and unbound forms. Most testosterone in the blood is bound to SHBG or albumin. Only free testosterone (about 1 to 2 percent) and some loosely bound testosterone can enter cells and exert effects.

Free testosterone can be measured directly or calculated using total testosterone and SHBG levels. A free testosterone level below 5 ng/dL (0.17 nmol/L) is often considered low, though reference ranges vary. Biomarkers Explained provides a broader overview of how these measurements fit into overall health assessment.

Salivary testosterone tests are also available but are less standardized. For accurate results, stick with blood tests drawn in the morning after a good night’s sleep.

What Happens When Testosterone Is Low?

Low testosterone, or hypogonadism, can cause decreased libido, erectile dysfunction, fatigue, loss of muscle mass, increased body fat, and mood changes such as depression. It may also contribute to reduced bone density and anemia. These symptoms overlap with normal aging, so laboratory confirmation is essential.

Hypogonadism can be primary (testicular failure) or secondary (pituitary or hypothalamic dysfunction). A full evaluation includes measuring luteinizing hormone (LH) and follicle stimulating hormone (FSH) to identify the cause. Treatment options include testosterone replacement therapy, lifestyle changes, and addressing underlying conditions.

It is important to note that many men with slightly low testosterone do not experience problems, and some men with normal testosterone do experience low testosterone symptoms. That is why the combination of lab values and symptoms guides diagnosis.

When Should Men Get Their Testosterone Levels Checked?

Men with persistent symptoms of low testosterone or certain medical conditions should consider testing, ideally with a morning blood draw. The Endocrine Society recommends testing in men with signs such as reduced sex drive, erectile dysfunction, osteoporosis, or pituitary disorders. Also consider testing if you have conditions like obesity, diabetes, or sleep apnea, which are linked to lower testosterone.

Routine screening in all men is not recommended. Many professional guidelines advise against testing in asymptomatic men or men with vague complaints. If you have concerns, discuss them with your healthcare provider. Testing outside of symptoms can lead to unnecessary treatment or anxiety.

For the most reliable results, avoid heavy meals, alcohol, and intense exercise the night before. Some medications, including opioids and steroids, can artificially lower testosterone levels.

What Factors Can Affect Testosterone Levels?

Obesity, poor sleep, chronic stress, alcohol, medications, and chronic illness can all lower testosterone levels. Unlike the slow decline of aging, these factors can cause rapid, reversible drops. For example, men with obesity often have lower total and free testosterone due to increased conversion of testosterone to estrogen in fat tissue.

Sleep deprivation is a well-established cause. Even a few days of reduced sleep can lower morning testosterone by 10 to 30 percent. Similarly, high stress raises cortisol, which suppresses testosterone production. Opioids, corticosteroids, and some antidepressants also interfere with the hypothalamic pituitary gonadal axis.

Lifestyle improvements such as regular exercise, weight loss, stress management, and 7 to 8 hours of quality sleep can often raise testosterone modestly without medication. However, these changes may not restore levels to normal if an underlying medical condition is present.

Frequently Asked Questions

What is the best age to test testosterone?

There is no single best age. Testing is recommended when symptoms of low testosterone appear, regardless of age. For most men, symptoms become more noticeable after age 40 or 50. Routine screening before age 40 is not advised unless you have specific risk factors such as pituitary disease, testicular injury, or use of medications that affect testosterone. If you are in your 30s and have unexplained low libido or erectile dysfunction, a morning test may be warranted.

Can testosterone levels vary day to day?

Yes, testosterone levels fluctuate daily and even within the same day. The highest levels occur in the early morning, usually between 7 a.m. and 10 a.m., and can drop by 25 to 30 percent by the afternoon. Levels can also vary depending on sleep quality, recent exercise, and stress. This is why guidelines recommend two separate morning tests before diagnosing low testosterone. Single random measurements are unreliable and may lead to misdiagnosis.

Is it normal for testosterone to drop after 50?

Yes, a gradual decline is normal. After age 50, average total testosterone decreases roughly 1 to 2 percent per year, while free testosterone declines even faster due to rising SHBG. Many men in their 50s, 60s, and beyond still have testosterone levels within the normal range. However, a drop that is steep or accompanied by bothersome symptoms should be evaluated. Healthy aging alone does not usually cause levels to fall below 300 ng/dL, but some decline is expected and does not automatically require treatment.

This article is for general information and is not medical advice. See our Medical Disclaimer.