Introduction Dog Day is a traditional Chinese medicine for curing diseases. As the name suggests, it is most effective when used during the \”Dog Days\”. However, due to improper use, there will be many adverse reactions. Therefore, before using Sanfu Patch, you need to pay attention to the following 8 precautions to ensure your safety. Note 1: Choose the appropriate seasonal patch. It is an external patch that works best when used in the dog days of summer. However, for children, pregnant women, the elderly and other people, special attention needs to be paid when using Sanfu patch. You should choose the appropriate one for each season under the guidance of a physician.