How long do you have to take herceptin (trastuzumab)?

One year. In the us, the studies of Herceptin (trastuzumab) looked at a full year of treatment for patients with curable breast cancer. Herceptin (trastuzumab) is given every three weeks for 17 doses. But why a year? It was chosen at random. In finland, a similar study gave only 9 weeks of herceptin (trastuzumab)... And patients did just as well! so, a year or less is the best answer. You don't need more!