Testosterone - Normal, High, Low


The normal range for testosterone levels in men is broad and varies by stage of maturity and age.

It is normal for testosterone levels to slowly decline, usually after age 30. For men who are obese, chronically ill or use certain medications, testosterone may decrease more.

As a reference: 300 to 1,000 nanograms per deciliter (ng/dL) or 10.41 to 34.70 nanomoles per liter (nmol/L)

A low testosterone level (hypogonadism) may be due to:

  • Hypothalamic or pituitary disease
  • Genetic diseases that can cause decreased testosterone production in young men or testicular failure and infertility
  • Impaired testosterone production because of acquired damage to the testes, such as from alcoholism, physical injury, or viral diseases like mumps
  • Chronic disease, such as diabetes

Men who are diagnosed with consistently low testosterone levels and have related signs and symptoms may be prescribed testosterone replacement therapy by their healthcare providers.

However, testosterone supplements are not approved by the Food and Drug Administration to boost strength, athletic performance, or prevent problems from aging. Use for these purposes may be harmful.

Increased testosterone levels in males can indicate:

  • Testicular tumors
  • Adrenal tumors that are producing testosterone
  • Use of androgens (also called anabolic steroids)
  • Early puberty of unknown cause in boys
  • Congenital adrenal hyperplasia in babies and children



In women, testosterone levels are normally low.

As a reference: 15 to 70 ng/dL or 0.52 to 2.43 nmol/L

Increased testosterone levels can indicate:

  • PCOS
  • Ovarian or adrenal gland tumor
  • Congenital adrenal hyperplasia
* The Content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition.