Intramuscular injection is a common method of drug delivery. When injecting, the gluteus maximus muscle on top of the buttocks will be chosen for injection, mainly because the muscle of the gluteus maximus is hypertrophic, the bones cannot be hurt when injecting, the drug is easily absorbed after injection, there are no important large blood vessels passing from deep in the muscle, and it can also open important nerves, which is easy for the nurse to operate, so it is often chosen to be injected in the buttocks. If the amount of drug injected is not very large, you can also choose to inject in the deltoid muscle of the upper arm, which is also a commonly used injection site. Although the operation of intramuscular injection is not complicated, it is also easy to cause allergy and other adverse reactions after the drug is injected into the body. Without sterilization, it is easy to cause local inflammation, which will affect the absorption of the drug over time and also damage the muscle, so you need to go to a regular medical institution and receive treatment.