[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [Nursing](https://durgical.com/en/nursing/) › [Medications and dose calculation](https://durgical.com/en/nursing/areas/medication/) › Subcutaneous injection # Subcutaneous injection - Procedure A subcutaneous injection places the drug in the fat under the skin, where it is absorbed slowly; it is the usual route for insulin and heparin. Updated Nov 5, 2026 ## Key points - Sites: abdomen (away from the navel), outer upper arm, front of the thigh, upper buttock and back. - 45° angle in thin people and 90° when there is enough fat; pinch a fold. - Do not massage the site: after heparin, massage can cause a haematoma. - Rotate sites: for insulin, within the same region, to avoid skin hypertrophy; for heparin, to avoid bruising. - Insulin and heparin are high-alert: independent double check before giving. ## What it is The subcutaneous (SC) route delivers a small volume of drug into the fatty tissue between skin and muscle, where it is absorbed gradually. It is used for insulins, low-molecular-weight heparins and some vaccines. Common sites are the abdomen (away from the navel), the outer upper arm and the front of the thigh. A skin fold is pinched, the needle goes in at 45° or 90° depending on the fat layer, and the site is not massaged. ## Indications - Insulin and anticoagulants ordered subcutaneously. - Some vaccines given by this route. - Drugs given in a small volume. ## Contraindications and precautions - Do not inject into bruised, open or scarred skin, or where blood flow is poor (for example cellulitis). - Avoid the area around the navel and bony prominences. - Anticoagulants: check for active bleeding or abnormal clotting tests per protocol. - Insulin: know the blood glucose and the meal plan before giving it. ## Equipment - Prepared medication and medical order. - An insulin syringe marked in units (for insulin only) or a small syringe; a short, fine needle (25 to 31 gauge). - Alcohol swab and sterile gauze. - Clean gloves. - Sharps container. ## Step by step (and why) - Apply the rights and the double check if it is insulin or an anticoagulant — these are high-alert drugs. - Choose a site different from the last dose, within the same region for insulin — rotation prevents skin hypertrophy and bruising. - Clean the skin and let the alcohol dry — reduces infection and stinging. - Pinch a skin fold with the non-dominant hand — lifts fat away from muscle. - Insert the needle at 45° or 90° depending on the fat layer — leaves the drug in subcutaneous tissue. - Release the fold once the needle is in; with heparin or an insulin pen, hold it until just before withdrawing — the technique for each product. - Inject slowly and withdraw at the same angle — reduces pain. - Press gently with gauze without massaging — massage can cause a haematoma. - Discard the needle in the sharps container and document the site — allows rotation at the next dose. ## Complications - Bruising, especially with anticoagulants or if the site is massaged. - Skin hypertrophy at insulin sites that are not rotated. - Hypoglycaemia if insulin does not match meals or the wrong insulin is given. - Bleeding with anticoagulants. ## Next step: when to call for help - Sweating, tremor, confusion or low blood glucose after insulin: follow the hypoglycaemia protocol and report at once. - Bleeding gums, dark or red urine, or black stools on anticoagulants: tell the doctor. - A large or growing bruise at the site: report. - Doubt about the insulin type or dose: do not give it until clarified with the prescriber. ## Test yourself Think of the answer, then tap the question to see it. ## Why is the site not massaged after a subcutaneous heparin injection? Because massage can contribute to a haematoma. ## When is a 45° angle used for a subcutaneous injection? In thin people or those with little fat; with enough fat, 90° is used. ## What complication results from not rotating insulin sites? Thickening (hypertrophy) of the skin at the site; insulin sites are rotated within the same region. [Add to my cards (3)](https://durgical.app/estudiar/?add=/en/nursing/subcutaneous-injection/) ## Connections ## Related 3 - [Preparing parenteral medication: ampoules, vials and reconstitution](https://durgical.com/en/nursing/preparing-parenteral-medication-ampoules-vials-and-reconstitution/) - [Intramuscular injection: sites and technique](https://durgical.com/en/nursing/intramuscular-injection-sites-and-technique/) - [High-alert medications](https://durgical.com/en/nursing/high-alert-medications/) ## In Pharmacology 3 - [Insulins](https://durgical.com/en/pharmacology/classes/insulins/) - [Heparins](https://durgical.com/en/pharmacology/classes/heparins/) - [Enoxaparin](https://durgical.com/en/pharmacology/enoxaparin/) [← All of nursing](https://durgical.com/en/nursing/) Educational content for students; it does not replace your institution's protocols, supervised clinical training or a prescriber's order. Dose-calculation examples use made-up numbers: they are educational, not a clinical order. Sources: [Nursing Skills (Open RN), 18.5 Administering Subcutaneous Medications](https://med.libretexts.org/Bookshelves/Nursing/Nursing_Skills_(OpenRN)/18%3A_Administration_of_Parenteral_Medications/18.05%3A_Administering_Subcutaneous_Medications) (Open RN, Chippewa Valley Technical College (LibreTexts), 2022); [Nursing Skills (Open RN), 18.8 Checklists for Parenteral Medication Administration](https://med.libretexts.org/Bookshelves/Nursing/Nursing_Skills_(OpenRN)/18%3A_Administration_of_Parenteral_Medications/18.08%3A_Checklists_for_Parenteral_Medication_Administration) (Open RN, Chippewa Valley Technical College (LibreTexts), 2022); [Vaccine Administration (General Best Practice Guidelines for Immunization)](https://www.cdc.gov/vaccines/hcp/acip-recs/general-recs/administration.html) (Centers for Disease Control and Prevention (CDC), 2024). ## **Spotted a mistake?** We are always improving for the community. Tell us what is wrong and our team will review it. Report a mistake Representative model, for educational purposes only. --- Source: https://durgical.com/en/nursing/subcutaneous-injection/ License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/nursing/subcutaneous-injection/