The pain and discomfort of a C-section, especially uterus shrinking pain, only truly starts after the surgery. Research has shown that labor pain ranks first among all surgeries. There is currently effective pain-reduced labor for natural births, while painkillers are injected into the spinal cavity, an epidural is administered, or patient-controlled pain relief devices (morphine added to postoperative drip, PCA) are used after C-section, However, they often cause problems such as limitations on patient mobility or their being limited to in-hospital use, etc. Currently, the novel 7-day long-acting painkiller injection is highly effective for uterus shrinking pain, hence, pain is well controlled with C-sections. In addition, the long-acting 7-day painkiller injection can reduce the number and amount of painkillers taken to reduce the occurrence of related side effects, which is more in line with the current pain relief trend!