Vinblastine affects cells that are in the process of growing and dividing. Cancer cells grow and divide faster than other cells in the body, but unfortunately the normal cells in the body that grow and divide on a regular basis are affected as well, which causes the seemingly familiar chemotherapeutic side effects of hair loss (hair follicle cells), nausea and vomiting, and diarrhea. Patients may also experience constipation, cramping, weight loss, changes in taste and appetite, mouth sores, and anemia. Peripheral neuropathy, as mentioned above, is uncommon but very serious, with patients starting out feeling decreased sensation and numbness in the hands and feet, but may progress to difficulty walking.

Some people may also experience headaches, depression, and pain in the joints and muscles.

Many people receiving treatment with Vinblastine will become anemic, and have low counts of both their red and white blood cells. This will put them at risk for infection.

The side effects listed below are serious and need to be told to your doctor about within 24 hours of noticing them: vomiting more than four to five times in a day, diarrhea more than four to five times in a day, constipation, strange bleeding or bruising, bone pain, severe abdominal pain, sores on the lips or mouth, blood in the urine or stool (this can look like black or tarry stools)