A hormone, such as insulin or estrogen, is a substance released by
an organ or tissue that controls the activity of organs or cells in another
part of the body. The organs or glands that release hormones are part of the
Hormones may also be taken as medicines, such as birth control
pills or estrogen replacement therapy.
E. Gregory Thompson, MD - Internal Medicine & Brian D. O'Brien, MD - Internal Medicine & Alan C. Dalkin, MD - Endocrinology