Although we think of testosterone as associated with men’s health, the hormone also plays a role in women’s bodies. It is the primary sex hormone in males, produced primarily in the testicles, and it is responsible for men’s deeper voices, larger muscles and body hair. Without it, sperm could not be produced.

The normal level of testosterone in a healthy man varies from approximately 300 nanograms per deciliter (ng/dL) up to 1,000 ng/dL. This range varies by age. Testosterone rises in men during puberty and through their twenties, then decreases gradually after age 30. Older men are usually on the lower end of the spectrum. The decline of testosterone is called andropause, and it is sometimes called male menopause.

Male testosterone levels can also be affected by hypogonadism, a problem in the testicles or pituitary gland (which governs the testicles). Levels may also be lower in men who are obese, have an autoimmune disease or type 2 diabetes, or are abusing drugs or alcohol.

Women’s bodies produce testosterone in the ovaries and the adrenal glands, but normal levels in women are much lower, ranging from 15 to 70 ng/dL. As is true in men, testosterone levels fall as women age, and the decline can cause decreased libido, low energy, and depression.

Research indicates testosterone replacement therapy (HRT) may increase women’s sex drive, but the long-term affects are unknown. There is concern among some experts that HRT could raise the risk of breast cancer.

In men, hypogonadism may be an issue from birth, or it may develop later on because of injury or infection.

Symptoms of hypogonadism in infants include:

Ambiguous genitalia
Female genitalia (in a genetically male child)
Underdeveloped male genitalia

In boys of puberty age, symptoms include:

Lack of muscle mass development
No deepening of the voice
Lack of facial and body hair
Slow increase in size of penis and testicles
Arms and legs that grow out of proportion to the rest of the body

Symptoms of hypogonadism in adult men include:

Low sex drive
Erectile dysfunction (ED)
Sparse facial or body hair
Growth of breast tissue

In older men experiencing a decline in testosterone, symptoms include:

Decreased sex drive
Difficulty concentrating
Changes in sleep patterns

Of course, these symptoms are sufficiently nonspecific that they may be attributable to other factors.


A diagnosis of male hypogonadism is predicated on symptoms, testosterone blood levels, and other lab tests, as indicated. The condition is generally treated with HRT and other therapies.Men who are obese are encouraged to lose weight, and address possible underlying conditions such as type 2 diabetes.

Hormone replacement therapy is being widely prescribed for men with low testosterone, but the treatment is still controversial. Medical experts are encouraging further research.