What is Chemotherapy? - St. Jude The Basics of Blood

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Chemotherapy uses powerful medicines to attack cells that grow and multiply quickly such as cancer cells. It’s usually given by mouth (pill or liquid) or through a vein (intravenous or IV).

Chemotherapy causes fast-growing cells to die or stop growing.

Chemotherapy can kill cancer cells throughout the body even if they traveled away from the original tumor.

By destroying cancer cells or slowing down their growth, chemotherapy works to cure or control cancer. But chemotherapy also harms other healthy fast-growing cells in the body causing some side effects, such as hair loss and damage to lining of the digestive tract.