ANDROGENS: Androgens, such as testosterone, are male sex hormones that produce male sexual characteristics. Androgens are also present at low levels in women, although their function in women is not clearly understood.

Testosterone may be used to help women who experience a drop in sexual desire after going through menopause or to treat some conditions such as breast cancer. Androgens also are used to treat men whose hormone levels have decreased.

ANDROGENS AS A GENERIC TERM:

In generics terms, androgens are any natural or synthetic compound, usually a steroid hormone, that stimulates or controls the development and maintenance of masculine characteristics by binding to androgen receptors. This includes the activity of the male sex organs and development of male secondary sex characteristics. Androgens are also called androgenic hormones or testoids. Androgens are the original anabolic steroids and are the precursor of all estrogens. Estrogens are the female sex hormones.

The primary and most well-known androgen is testosterone.

TYPES OF ANDROGENS:

A subset of androgens called adrenal androgens, include any of the 19-carbon steroids synthesized by the adrenal cortex. The adrenal cortex is the outer portion of the adrenal gland. The adrenal glands sit on top of each kidney like tiny little party hats. Adrenal androgens function as weak steroids or steroid precursors, including dehydroepiandrosterone (DHEA), dehydroepiandrosterone sulfate (DHEA-S) and androstenedione.

In addition to testosterone, other androgens include:

Dehydroepiandrosterone (DHEA): This is a steroid hormone produced from cholesterol in the adrenal cortex, which is the primary precursor of natural estrogens.

DHEA is also called dehydroisoandrosterone or dehydroandrosterone.

Androstenedione (Andro): This is an androgenic steroid, which is produced by the testes, adrenal cortex, and ovaries. While androstenediones are converted metabolically to testosterone and other androgens, they are also the parent structure of estrone.

Any use of androstenedione as a supplement for athletic or body building purposes has been banned by the International Olympic Committee as well as other sport organizations.

Androstanediol: This is the steroid metabolite that is thought to act as the main regulator of gonadotropin secretion.

Androsterone: This is a chemical by-product created during the breakdown of androgens, or derived from progesterone that also exerts minor masculinizing effects, but with 1/7 the intensity of testosterone. It is found in approximately equal amounts in the plasma and urine of both males and females.

Dihydrotestosterone (DHT): This is a metabolite of testosterone that is a more potent androgen. It binds more strongly to androgen receptors.

ANDROGEN FUNCTIONS:

Male Development:

During development, the gonads (sex organs) are capable of first becoming either ovaries or testes. In humans, starting at about the 4th week of development the formation of the gonads are present. At about the 6th week of development, epithelial sex cords develop within the forming testes and incorporate the germ cells as they migrate into the gonads.

Androgens and the Inhibition of adipose (fat) deposition:

Males typically have less adipose (fat) tissue than females. Research indicates that androgens inhibit the ability of some fat cells to store lipids.

Muscle mass:

Males typically have more skeletal muscle mass than females. Research indicates that androgens promote the enlargement of skeletal muscle cells and may act in a coordinated manner to enhance muscle function. The research indicates that this is by acting on several cell types in skeletal muscle tissue.

Androgens and the Brain:

Research indicates that circulating levels of androgens can influence human behavior. This is because some neurons (nerve cells) are sensitive to steroid hormones. Research also indicates that androgen levels have been implicated in the regulation of our libido and in our aggression.