The Science of Hormone Disruption Hormones are chemical messengers produced by the endocrine glands such as the testicles, ovaries, thyroid, pituitary and adrenal glands in humans and wildlife.
Hormones inform cells about how and when to grow, produce bodily substances, divide and then die.
They are necessary for regulating many biological processes. In the embryo and fetus, hormones guide the development of sexual organs, nervous and immune systems, organs and tissues such as the liver, blood, kidneys, muscles, and the brain. At incredibly low concentrations, and with amazingly precise timing, hormones communicate their messages by binding to receptors in cells, like a lock and key. At equally low levels, some synthetic chemicals can interfere with this process, becoming hormone disruptors. As a result, the body's careful hormonal balance and messaging system can be thrown off track.