According to the Marshfield Clinic, the effects of chemotherapy last for different amounts of time, depending on the type of cancer, the patient's overall health and the type of treatment performed. Some side effects taper off in a few months while some may last for a lifetime.
The American Cancer Society mentions that chemotherapy drugs are eliminated from the body by the liver and kidneys. In part, the health of these organs determines the amount of time that the drugs spend in a patient's body. The doctor analyzes all risk factors and recommends the right type of chemotherapy for the patient, along with advising the patient about any necessary precautions.