The sex hormone testosterone is found mainly in the male body and only in small amounts in the female. Its concentration in the blood is measured to clarify various health disorders and diseases. Here you can read what those are, what testosterone levels are considered normal and what different readings can mean!

Article overview testosterone

  • What is testosterone?
  • When is the testosterone level determined?
  • Testosterone normal values
  • When is the testosterone level too low?
  • When is the testosterone level too high?

What is testosterone?

Testosterone is the most important male sex hormone (androgen). It is mainly produced in the testicles. In women, the ovaries and adrenal cortex produce low levels of testosterone. In addition, her body produces testosterone from precursors of other androgens.

Testosterone is mainly responsible for:

  • Development of the reproductive organs (testes, prostate, penis)
  • Training of typical male sexual characteristics (hairiness, deep voice, specific fat distribution)
  • male habit
  • seed production
  • Control of male pleasure and activity
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When is the testosterone level determined?

Testosterone is determined at:

  • impotence
  • Suspected hypofunction of the male gonads (hypogonadism)
  • Suspected adrenal cortex tumors
  • Suspected adrenal gland syndrome in children
  • Suspected congenital hyperfunction of the adrenal cortex (congenital adrenal hyperplasia)
  • Disorders of puberty development
  • Suspected testicular tumor
  • Therapy with antiandrogens for therapy control (for example in prostate cancer)
  • Women with signs of masculinization: male hair pattern (hirsutism), acne, hair loss
  • Women who did not ovulate for a long time
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Testosterone normal values

Testosterone is determined from the blood serum. Since the testosterone level fluctuates during the day, the blood should be taken between eight and ten o'clock in the morning. There are usually three blood samples taken at intervals of 20 to 30 minutes: the serum from all three blood samples is pooled together. From this "pool serum" then the testosterone is determined, and usually the Total testosterone (most of the hormone is bound to proteins in the blood, only a small part circulates freely). The following standard values ​​apply:





0.04-0.20 μg / l

0.05 - 3.50 μg / l

1 to 8 years

0.03 - 0.12 μg / l

0.05-0.15 μg / l

9 to 12 years

0.03-0.40 μg / l

0.10 - 3.0 μg / l

13 to 18 years

0.06 - 0.50 μg / l

0.10 - 9.0 μg / l


0.15-0.55 μg / l

3.5 - 9.0 μg / l

Conversion: μg / l x 3.467 = nmol / l

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When is the testosterone level too low?

Too low testosterone levels in men can occur in the following cases:

  • Hypofunction of the gonads (e.g., Klinefelter syndrome)
  • Taking anabolic steroids
  • cirrhosis
  • substance abuse
  • severe malnutrition / anorexia nervosa

For women, low testosterone levels may be due to:

  • Hypofunction of the ovaries (ovarian failure)
  • Therapy with antiandrogens
  • Taking ovulation inhibitors or estrogens
  • Addison's disease
  • cirrhosis
  • Substance abuse, anabolic steroids
  • severe malnutrition / anorexia nervosa