In the last issue of WeChat, we talked about how insulin injection sites should be selected from areas rich in subcutaneous fat, which include the abdomen, outer thighs, outer upper arms and outer upper arms. In the abdomen, the injection should be avoided in a circular area with the umbilicus as the center and a radius of 5 cm. 5 cm, which is about the width of the 3 fingers of the index, middle and ring fingers together. In addition, the variability of insulin absorption in different sites should be considered. The rate of insulin absorption varies from one injection site to another, with the abdomen being the fastest, followed by the upper arm, thighs and buttocks in that order. In this issue of WeChat, we talk about the rotation of insulin injection sites. Repeatedly injecting insulin at the same site will lead to subcutaneous fat growth and hard nodules at that site, and injecting insulin at that site will lead to a decrease in drug absorption rate and prolonged absorption time, which in turn will lead to blood sugar fluctuations. Therefore, it is important to pay attention to the rotation of injection sites during the usual injections. This rotation includes rotation between different injection sites and rotation within the same injection site. Recommended: a proven injection site rotation protocol: divide the injection site into four aliquots (thighs or buttocks can be divided into two aliquots) and use one aliquot per week and always rotate in a clockwise direction. When injecting in any of the aliquots, each injection site should be at least 1 cm apart to avoid repeated tissue damage. Patients should be taught a simple and easy to follow injection site rotation protocol from the very beginning of injection therapy. Each time a patient is seen, the healthcare provider should check the implementation of the patient’s rotation plan. The rate of insulin absorption varies with different injection sites. Therefore, in order to accurately predict the efficacy of insulin after each injection, it is necessary to strictly adhere to the “same injection site at the same time every day”, “different injection sites at different times every day” or “left-right rotation”. “. Once pain, depression, or hard knots are found at the injection site, the injection should be stopped immediately until the symptoms disappear. Patients should check the injection site before injection. Once subcutaneous fatty growth, inflammation or infection is found at the injection site, the injection site should be replaced. When injecting, the injection site should be kept clean. When the injection site is unclean, or if the patient is in an environment where infection can be easily spread (e.g., hospital or nursing home), the injection site should be disinfected before injection.