Your body normally protects you by attacking anything that seems foreign or doesn’t belong. This helps you stay healthy and fight infections. After your transplant, your body will see your new kidney as foreign and may try to attack it. This is called rejection.
To stop this from happening, you must take anti‑rejection medicines (also called immunosuppressants). Anti-rejection medicines act on the body’s immune system. They reduce the body’s ability to either detect foreign substances or fight off attacks. You will need to take these for the whole time your transplanted kidney is working. Without them, your body is very likely to reject the kidney. It is very important that you do not miss any doses or stop taking these medicines unless the kidney transplant team tells you to.
Anti-rejection medicines weaken your immune system, which means your body cannot fight infections as well. All transplant patients have a higher risk of infection compared to people not taking immunosuppression medicines. This is especially true during the first few months following the transplant, when doses or amounts of anti-rejection medicines are at their highest. Infection can be just as life threatening as rejection and should be taken very seriously.
Immunosuppressants can also increase the risk of other health problems, such as skin cancer and diabetes. The kidney transplant team will explain these risks to you and answer any questions you have.
Last reviewed: 24 March 2026