Hormones are proteins that influence growth and development in the body. Unfortunately, some cancer types, like those of the breast and prostate, also depend on hormones for their growth. Therefore, stopping or blocking the production of certain hormone in the body can help reduce the growth of these cancer cells. This is known as hormone therapy. Hormone therapy is systemic; it only targets specific cells in our body which are hormone receptor positive. It works in a variety of ways like it prevents the hormone from attaching itself to cancer cells or altering the hormones so that they do not facilitate the growth of cancer, or it may block the production of the hormone. The effectiveness of hormone therapy depends on the type and spread of cancer. It is often used along with radiation therapy, chemotherapy, and surgery. It can be administered before surgery to reduce the size of the tumour (known as neoadjuvant therapy), after surgery or radiotherapy to avoid cancer recurrence (known as adjuvant therapy), or it can be used to treat recurrent cancers and metastatic cancers (known as palliative hormone therapy).