Nolvadex (tamoxifen citrate) is prescribed to treat breast cancer in female patients. You may be required to take this medicine for up to 5 years, so any health conditions you have, as well as drugs you are taking or may be required to take should be discussed with your doctor. Side effects of Nolvadex can be different for different people, but the most common ones include nausea, vomiting and hot flashes. If these side effects become bothersome and do not go away on their own talk to your doctor about them. Only your health care provider can decide whether you should continue the treatment or stop it due to the side effects.