Last updated: March 30, 2022

Summarytoggle arrow icon

Androgens (male sex hormones) play a key role in the development and function of the male reproductive system. They are furthermore responsible for the development of skeletal muscle mass, bone density, and erythropoiesis. Testosterone is the main androgen and anabolic steroid in male individuals, in whom it is secreted primarily by Leydig cells in the testicles. In female individuals, testosterone acts as an estrogen precursor and is secreted by theca interstitial cells in the ovaries. Other androgens include androstenedione and dehydroepiandrosterone (DHEA), which are secreted in the adrenal cortex. The production of androgens is controlled by the hypothalamic-pituitary-gonadal axis (HPG axis), whose function can be impaired by a deficiency or excess of testosterone. The clinical manifestations of these dysfunctions depend on the stage of development in which the imbalance occurs. Testosterone deficiency during embryonic development leads to the feminization of the male external genitalia. In the prepubescent phase, it can cause hypogonadism and delayed puberty associated with delayed constitutional growth. After puberty, testosterone deficiency can cause infertility. Synthetic androgens (anabolic-androgenic steroids) are used to treat the effects of testosterone deficiency (e.g., delayed puberty) and diseases associated with muscle loss (e.g., cancer, acquired immunodeficiency syndrome). Long-term effects of anabolic-androgenic steroids, frequently seen in individuals who misuse them to promote muscle growth, include liver and kidney damage, cardiomegaly, behavioral changes (e.g., paranoia, aggression), and hypogonadism.

For more information on androgens and their clinical relevance, see the articles on “General endocrinology,” "Adrenal gland,” “Male reproductive organs,” “Differences (disorders) of sex development,” and “Development of the reproductive system.”

Overviewtoggle arrow icon

Overview of androgens

Dihydrotestosterone (DHT)

Androstenedione Dehydroepiandrosterone (DHEA)

Overview of androgen synthesistoggle arrow icon

Testosterone synthesis

Testosterone synthesis takes place in the testicles.

Adrenal androgen synthesis

Although the majority of testosterone is produced by the Leydig cells in the testicles, the adrenal cortex contributes to androgen production as well.

Feedback control mechanisms

The testosterone and estrogen precursors DHEA and androstenedione are produced in the adrenal cortex in both male and female individuals. Testosterone is produced by Leydig cells in the testicles and, to a lesser degree, by the theca interstitial cells in the ovaries.

AnDRostenedione is produced by the ADRenal glands and TESTostetone by the TESTicles.

Anabolic–androgenic steroidstoggle arrow icon

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