In most cases, there is not an interaction between most drugs or supplements and radiation therapy. Chemotherapy agents are an important exception and your radiation oncologist will work closely with your chemotherapy doctor in cases where chemotherapy and radiation are given at the same time. Your doctor will need to have a complete list of all of your medications and supplements so you can be informed of any potential interactions. If you start or stop a medication or supplement during treatment, please let your radiation oncologist or nurse know so that we can keep your medication record up to date and provide you with advice if needed.