The present invention provides a composition for mitigating anticancer drug side effects, the composition containing isoleucine, leucine and valine as active ingredients. The composition is extremely safe and moreover will not impact the anticancer effects of an anticancer drug, therefore making it possible to enhance the cancer-treating effects imparted by administering the anticancer drug.本發明係提供含有異白胺酸、白胺酸及纈胺酸作為有效成份之抗癌劑副作用改善用組成物。因為該組成物係安全性極高，且不影響抗癌劑之抗癌作用，所以可提高藉由投予抗癌劑之癌治療效果。
