What Are Healthy Levels of Testosterone?

What Testosterone Does in the Body

Testosterone is a hormone involved in many bodily processes, from building male reproductive tissue to supporting muscle growth and preserving bone density. It also plays a part in producing other hormones, such as estrogen and progesterone. Levels rise and fall over the course of a day and are influenced by age, general health, and lifestyle.

Mostly made in the testicles, testosterone drives male physical development. Readings vary from person to person and depend on age, body weight, and activity level. In the average adult male, a normal range is roughly 300 to 1,000 nanograms per deciliter (ng/dL). A result below 300 ng/dL is usually considered low and may come with less muscle mass, a lower sex drive, and other symptoms. A result above 1,000 ng/dL is considered high and may be associated with increased aggression, acne, and other effects.

Effects of Abnormal Testosterone Levels

Testosterone is important for both men and women, though it is most often linked to male development and function. It supports sexual and reproductive development, bone and muscle strength, and general health and well-being. When levels rise too high or fall too low, health can be clearly affected.

Many people are familiar with testosterone and its effects on the body without fully understanding what it is or how it works. Because testosterone drives male sexual characteristics, abnormal levels can have a significant impact. Symptoms may include a lower sex drive, erectile dysfunction, and infertility.

A small amount of testosterone is also produced by the adrenal glands, a source called "adrenal androgen." Levels can be affected by age, illness, injury, and medications. Abnormal levels may cause symptoms such as:

  • Low sex drive
  • Difficulty getting or maintaining an erection
  • Infertility
  • Breast development
  • Decreased muscle mass
  • Osteoporosis
  • Fatigue
  • Depression

What Causes High Testosterone Levels

When testosterone levels rise in men and women alike, it helps to know what this hormone is and what pushes its levels upward. Testosterone is a sex hormone responsible for male traits such as facial hair and a deeper voice, and it also contributes to muscle development and sex drive. In men, levels typically peak in the early morning and decline through the day, though they can vary from day to day and from person to person. Contributing factors include:

  • Muscle mass
  • Facial hair growth
  • Aggression

What Causes Low Testosterone Levels

"Low T," or low testosterone, has drawn a great deal of discussion. This hormone is essential for many functions in the male body, including sexual development and function, bone and muscle mass, and hair growth. Low levels can lead to problems such as:

  • Fatigue
  • Depression
  • Decreased sex drive

Several factors can contribute to low testosterone. Age is one: levels naturally decline as men get older. Other possible causes include obesity, sleep deprivation, and stress, and certain medications can also lower testosterone levels.

What Influences Testosterone Levels

Testosterone is produced mainly in the testes and also in the adrenal glands, and it is responsible for male characteristics. Levels vary throughout the day but tend to be highest in the morning.

Many factors can affect testosterone, including age, health, stress, weight, diet, medications, injuries, and lifestyle choices. For example, levels naturally decline as men age, and this decline can be sped up by conditions such as obesity and type 2 diabetes. Lifestyle habits like smoking and heavy alcohol consumption can also drive levels lower.

How to Keep Testosterone Levels Healthy

Testosterone is a male sex hormone central to many body processes. It supports the development of male reproductive tissues and sexual characteristics, builds muscle mass, and helps maintain bone density and red blood cell levels. Levels generally peak during adolescence and early adulthood, then may start to decline after age 30.

Lifestyle choices, health conditions, and medications can all affect testosterone. Regular exercise and a healthy diet can help keep levels up, and avoiding smoking and excessive alcohol consumption is just as important. If you are considering additional treatment options, you can review testosterone clinical trials at Power.

Explore Testosterone Clinical Trials

For further reading on testosterone research, see this ScienceDaily report.

Testosterone Levels: Common Questions

What counts as a normal testosterone level?
In the average adult male, levels fall between 300 and 1,000 nanograms per deciliter (ng/dL). Results below 300 ng/dL are generally considered low, while results above 1,000 ng/dL are considered high. Because levels vary between people and throughout the day, a single reading should be interpreted by a healthcare professional.
Which symptoms can abnormal testosterone levels cause?
Abnormal levels can contribute to symptoms such as low sex drive, trouble getting or keeping an erection, infertility, breast development, reduced muscle mass, osteoporosis, fatigue, and depression.
What factors influence testosterone levels?
Levels can be affected by age, health, stress, weight, diet, medications, injuries, and lifestyle choices. They also vary throughout the day and are usually highest in the morning.
What leads to low testosterone?
Possible causes include natural age-related decline, obesity, sleep deprivation, stress, and certain medications.
How can you maintain healthy testosterone levels?
Regular exercise and a healthy diet can help keep testosterone levels healthy. Avoiding factors that lower testosterone, such as smoking and excessive alcohol consumption, is also important.

Testosterone readings are only one part of the picture. Because levels shift throughout the day and differ from person to person, a single result is best reviewed alongside your symptoms, health history, and lifestyle. If you have concerns about your levels, a healthcare professional can help you interpret your results and decide on next steps.