Herceptin, or Trastuzumab, should be given as many as 17 doses as the patient’s body tolerates to effectively prevent recurrence and metastasis. Trastuzumab is mainly used to treat HER2 overexpression breast cancer. The dosing regimen is to repeat every 3 weeks, and it needs to be used for a full year’s time, i.e. 17 times. Numerous clinical studies have confirmed that trastuzumab should be administered as many times as possible in order to effectively prevent tumor recurrence and metastasis, relieve symptoms and prolong life. The common adverse reactions of trastuzumab include infusion reaction, fever, nausea, vomiting, diarrhea, cardiotoxicity, etc. It is prohibited for those who are allergic to it. If you need to apply, standardize the application under the guidance of a physician.