How to Prepare and Give Subcutaneous Injection. The need to know how to properly prepare and administer an injection of medicine to a patient is invaluable. As with all procedures, you want to make sure to identify the patient correctly, explain the procedure to the patient, have freshly washed hands and organized equipment. For example, if you are administering insulin, you will want to have a 1cc syringe on hand. Also be sure to double check the label on the medicine bottle and the expiration date. Wipe down the top of the bottle with an alcohol swab and prepare your syringe. Be sure to know the precise amount the doctor has prescribed and only fill the syringe that far. Once you have your medication measured out and ready, don your disposable gloves to stay safe while administering the medication to your patient. Choose your site for the injection – insulin can be injected in the arm, the belly or the thigh – and clean/prep the area. At a 45 degree angle, insert the needle and push the stopper to inject the medication slowly. Do not inject the medication quickly or it can cause discomfort for the patient. For patients who are quite large or who have large muscles, it can be difficult to get the syringe to pierce the skin at a 45 degree angle. If this happens, try it at a 90 degree angle. After the syringe is empty, clean and gently massage the area and then apply a bandage or band-aid if necessary.