Hormones are substances produced naturally in the body. They act as chemical messengers and influence the growth and activity of cells.
Hormones are produced by a number of different organs and glands, which together are known as the endocrine system.
Hormonal therapies work by altering the production or activity of particular hormones in the body. They are most commonly used to treat breast cancer and prostate cancer. The type of hormone therapy given depends on the type of cancer being treated.
There are several different types of hormonal therapy. They are usually given as either tablets or injections. The side effects will vary and depend on the individual drug.
General side effects can include tiredness, headaches, feeling sick and muscle or joint aches.
For more detailed information about a particular treatment, you can use our list of treatments to find it.