Do strong side effects mean chemotherapy is working?

No. You cannot tell if chemotherapy is working based on its side effects.

Some people think that severe side effects mean chemotherapy is working well, or that having no side effects means it is not working. Neither is true. Side effects have nothing to do with how well chemotherapy is fighting your cancer.

To check whether chemotherapy is working, your doctor will see you often. They will ask how you feel, do a physical exam, and order tests and scans. These might include blood tests and imaging scans such as MRI, CT, or PET.

If you are worried that mild or missing side effects mean your treatment is not helping, talk with your care team. They can explain what your test results show.