Anabolic steroids have therapeutic use and may be prescribed to treat problems such as muscle degeneration associated with disease, male hormone issues, and late onset of puberty. However, some individuals use anabolic steroids illegally to improve athletic performance and build muscle mass. Abuse of anabolic steroid hormones disrupts the normal production of hormones in the body. There are several negative health consequences associated with anabolic steroid abuse. Some of these include infertility, hair loss, breast development in males, heart attacks, and liver tumors . Anabolic steroids also effect the brain causing mood swings and depression.
The formation of the corpus luteum (which produces the majority of progesterone) is triggered by a surge in luteinising hormone production by the anterior pituitary gland . This normally occurs at approximately day 14 of the menstrual cycle and it stimulates the release of an egg from the ovary and the formation of the corpus luteum. The corpus luteum then releases progesterone, which prepares the body for pregnancy. If the egg is not fertilised and no embryo is conceived, the corpus luteum breaks down and the production of progesterone decreases. As the lining of the womb is no longer maintained by progesterone from the corpus luteum, it breaks away and menstrual bleeding occurs, marking the start of a new menstrual cycle.
Steroid hormones are synthesized from cholesterol in the gonads and adrenal glands. A quick glance at their structures ( Figs. – ) shows how closely they resemble cholesterol (and one another) and therefore are lipids that are at home in membranes. They can readily move about laterally, undergo flip-flop and can pass through membranes until they encounter their appropriate steroid hormone receptor in the cytosol or nucleus [41,43] . In the cytosol, the steroid hormone may or may not be further enzymatically modified and can then bind to its receptor. The steroid hormone–receptor complex can immediately alter intracellular metabolic events by rapid, nongenomic mechanisms  . Alternatively, some steroid hormones bind to nuclear receptors  . The nuclear steroid hormone–receptor complex then binds to specific DNA sequences, inducing transcription of its target genes. This instigates slow-acting genomic responses. In either case, the hormone–receptor complexes cause changes in the target cell's basic physiology. With limited water-solubility, steroid hormones must be transported through the blood bound to specific carrier proteins.