Insulin can be injected subcutaneously in the buttocks or lateral thighs, care should be taken to sterilize the injection site and avoid repeated injections in the same area. Insulin injection is mainly used for subcutaneous injection to reach the subcutaneous fat layer for absorption. Abdomen, outer thighs, buttocks, outer upper arms and other areas rich in fat can be injected. Since the absorption rate is fastest in the abdomen, fast-acting and short-acting insulin can be injected in the abdomen as much as possible, while intermediate-acting and long-acting insulin can be injected in the outer thighs. In summary, insulin is injected subcutaneously, and the outer thighs are rich in subcutaneous fat, so insulin can be injected in the outer thighs. For the specific dosage and injection method, it should be carried out under the guidance of professional doctors.