Steroid

A steroid is a organic compound, either natural or man-made, which has four cycloalkane rings in its structure. Plants, animals and fungi make hundreds of different natural steroids.

Four steroids

Steroid numbering

Steroid hormones are steroids which act as hormones in the body. Natural steroid hormones are usually made from cholesterol in the adrenal glands and gonads. Cholesterol is a plentiful steroid in animal cells: it is important for cell membranes.

Examples of steroid hormones include

• estrogen,
• testosterone,
• progesterone,
• Vitamin D₃ or cholecalciferol.

One review noted: The adrenal gland hormones play a vital role in adapting to "ever-changing environmental and emergency situations, and help vertebrates in their successful survival".

Prednisone is an important man-made steroid medication, used to treat inflammation.

Medical use

Some steroid hormones are anabolic steroids (AAS). Since the discovery and synthesis of testosterone in the 1930s, AAS have been used by physicians for many purposes, with varying degrees of success, including:

• Bone marrow stimulation: For decades, AAS were the mainstay of therapy for hypoplastic anemias due to leukemia or kidney failure, especially aplastic anemia. AAS have largely been replaced in this work by synthetic protein hormones that stimulate growth of blood cell precursors.
• Growth stimulation: AAS can be used by pediatric endocrinologists to treat children with growth failure. However, the availability of synthetic growth hormone, which has fewer side effects, makes this a secondary treatment.
• Stimulation of appetite and preservation and increase of muscle mass: AAS have been given to people with chronic wasting conditions such as cancer and AIDS.
• Hormone replacement for men with low levels of testosterone; also effective in improving libido for elderly males.
• Stimulation of lean body mass and prevention of bone loss in elderly men, as some studies indicate. However, a 2006 placebo-controlled trial of low-dose testosterone supplementation in elderly men with low levels of testosterone found no benefit on body composition, physical performance, insulin sensitivity, or quality of life.
• Induction of male puberty: Androgens are given to many boys distressed about extreme delay of puberty. Testosterone is now nearly the only androgen used for this purpose and has been shown to increase height, weight, and fat-free mass in boys with delayed puberty.
• Gender dysphoria, by producing secondary male characteristics, such as a deeper voice, increased bone and muscle mass, facial hair, and clitoral enlargement in transgender men, among females or those who develop female secondary sexual characteristics but desire to rather be read as male or look more ambiguous, such as a number of non-binary transgender people, both intersex and dyadic, and dysphoric non-transgender intersex men.
• In low doses as a component of hormone replacement therapy for postmenopausal and transgender women, for instance to increase energy, well-being, libido, and quality of life, as well as to reduce hot flashes. Testosterone is usually used for this purpose, although methyltestosterone is also used.
• Treatment of osteoporosis in postmenopausal women. Although they have previously been approved for this indication, AAS saw very little use for this purpose due to their virilizing side effects.
• Treatment of breast cancer in women, although they are now rarely used for this purpose due to virilizing side effects.
• Male contraception, in the form of testosterone enanthate; potential for use in the near-future as a safe, reliable, and reversible male contraceptive.

Abuse

Certain anabolic steroids, such as testosterone, are used as drugs to help make muscles stronger. Such steroids are used to improve a person's performance, but they are sometimes overused and abused by athletes that depend on them. The rate of steroid abuse grew greatly in the early 21st century, all over the world. Anabolic steroids can have very bad effects on the human body. They can cripple or kill. Some sports forbid them.

Related pages

• Doping in sport
• Adrenal gland

Other websites

• US National Library of Medicine National Institutes of Health
• National Institute on Drug Abuse (NIDA) NIDA
• steroids in sport Steroids in sport journal
• Corticosteroids Medline Plus

Steroid Resources
Latest articles Most recent articles Ongoing trials	Wikipedia