In laboratory studies, glands can be removed or hormones can be administered to study the effect on animals, such as rats or mice. Human diseases or inherited disorders, which involve hormone imbalance, are studied to better understand the resulting dysfunction and to develop treatments. For example, it is known that men produce small amounts of estrogen and women produce small amounts of testosterone. Too much estrogen in a man results in female characteristics such as enlarged breasts. Too much testosterone in a woman results in male characteristics such as facial hair.
Hormone imbalance can be life threatening, as with insulin and diabetes.
Estrogen imbalance has been implicated in certain forms of breast cancer. Many endocrine disruptors are thought to mimic hormones. They have chemical properties similar to hormones that allows binding to hormone specific receptors on the cells of target organs. Most endocrine disruptors have very low potency as their chemistry is significantly different from the hormones they mimic. Lower potency means that a greater amount of endocrine disruptor is required to elicit the same response of the hormone they mimic.