Steroid Hormones

Steroid hormones are steroids that act as hormones. Steroid hormones can be grouped into five groups by the receptors to which they bind: glucocorticoids, mineralocorticoids, androgens, estrogens, and progestagens. Vitamin D derivatives are a sixth closely-related hormone system with homologous receptors, though technically sterols rather than steroids.

The natural steroid hormones are generally synthesized from cholesterol in the gonads and adrenal glands. These forms of hormones are lipids. They can pass through the cell membrane as they are fat-soluble, and then quite easily combine with a protein receptor which may be nuclear of cytosolic depending on the steroid hormone, to bring about changes within the cell. Steroid hormones are generally carried in the blood bound to specific carrier proteins such as sex hormone-binding globulin or corticosteroid-binding globulin. Further conversions and catabolism occurs in the liver, in other "peripheral" tissues, and in the target tissues.

A variety of synthetic steroids and sterols have also been contrived. Most are steroids, but some non-steroidal molecules can interact with the steroid receptors because of a similarity of shape. Some synthetic steroids are weaker, and some much stronger, than the natural steroids whose receptors they activate.

Some examples of synthetic steroid hormones:
Glucocorticoids: prednisone, dexamethasone, triamcinolone
Mineralocorticoid: fludrocortisone
Vitamin D: dihydrotachysterol
Androgens: oxandrolone, nandrolone (also known as anabolic steroids)
Estrogens: diethylstilbestrol (DES)
Progestins: norethindrone, medroxyprogesterone acetate

Steroids are primarily used by bodybuilders, athletes, and fitness buffs who claim steroids give them a competitive advantage and/or improve their physical performance. Also, individuals in occupations requiring enhanced physical strength (body guards, construction workers, and law enforcement officers) are known to take these drugs. However, steroid misuse or abuse has been associated with health problems and undesirable outcomes.

Side effects of steroid use can include hair loss, liver problems, insomnia, acne, headaches, jaundice, hypertension and high cholesterol. Men who use steroids can experience shrinking testes, gynaecomastia (enlarged breasts) and prostate and fertility problems. Females may experience a deepened voice, increases in body and facial hair, menstrual irregularities, and an enlarged clitoris. Males may experience testicle shrinkage, infertility, and breast development. In addition several psychological effects, such as increased aggression and hostility, irritability, anxiety, paranoia, mood swings, depression, and suicidal thoughts may also occur. Steroids can permanently stunt the growth of adolescents.

Steroid abuse can have profound effects on the mind, causing temporary personality changes in some. Psychological side effects of steroids include irritability, agitation, euphoria or depression. Insomnia can also be a side effect. These changes in appearance and mood are often more apparent with high doses of steroids.

Steroids may also cause a redistribution of fat, leading to a swollen face and abdomen, but thin arms and legs. An increase in susceptibility to infections may occur with high doses of steroids. Steroids reduce calcium absorption through the gastrointestinal tract which may result in osteoporosis, or thinning of the bones. Prolonged heavy use of steroids can permanently damage the liver, causing cancer, jaundice, bleeding, and hepatitis.