Under the skin,
step by step.
A visual companion for understanding a prescribed subcutaneous medicine. Subcutaneous means the fatty layer just beneath the skin.
Have a clinician demonstrate your exact medicine and device before your first injection. Follow its Instructions for Use and your prescription. This guide cannot establish whether a research-labeled peptide is suitable for human use, choose your dose, or replace practical training.
Find a compound’s source documents →A syringe, a pen and an autoinjector work differently.
The illustrations below describe general manual-syringe concepts. Filling a vial syringe, priming a pen, leaving an air bubble in certain prefilled syringes, and holding an autoinjector in place all depend on the product. Use its instructions for preparation, bubble handling, needle choice, timing and any mixing. Do not withdraw medicine from a pen unless the manufacturer and your clinician expressly instruct it.
- 01
Prepare a clean space.
Wash and dry your hands. Set out the prescribed medicine, the correct sterile device, alcohol wipes, gauze and an accessible sharps container. Use a fresh needle and syringe for every injection; keep the preparation area away from sinks and contamination.
Why it matters Have disposal ready before uncovering a needle.
CDC preparation and single-use guidance ↗ - 02
Check the medicine and device.
Match the label to your prescription: medicine, formulation, concentration, dose, route and expiry. Check packaging and the appearance required by the product instructions. Ask your pharmacist to resolve any mismatch before proceeding.
Why it matters A calculator result cannot verify identity, sterility or the prescription.
MSK patient instructions ↗ - 03
Choose and rotate the site.
Use a site permitted by the exact product, such as the abdomen or outer thigh when its instructions allow. Avoid damaged, red, bruised or scarred skin. Change the location between injections; observe the product’s distance from the navel.
Why it matters A medicine’s allowed sites take priority over a generic body diagram.
MedlinePlus site guidance ↗ - 04
Clean and allow to dry.
Clean the chosen skin with an alcohol wipe and let it air dry. Keep the exposed needle sterile: do not touch it or let it contact a surface. If it becomes contaminated, use a new sterile device and ask about replacing the medicine.
Why it matters Blowing on the site or touching the needle can reintroduce contamination.
MSK cleaning and needle handling ↗ - 05
Use the technique you were taught.
For a manual subcutaneous syringe, clinician training may include gently pinching a skin-and-fat fold, then inserting at the taught angle and depth. Guidance describes 90° or 45° depending on fatty tissue; the device and your clinician determine the appropriate technique. Push the plunger to deliver the prescribed amount and withdraw as instructed.
Why it matters The intended layer is fat under the skin. This drawing is not a depth or angle measurement.
MedlinePlus manual-syringe technique ↗ - 06
Finish and dispose safely.
If needed, hold gentle gauze pressure. Put the used needle and syringe directly into a sharps container. Do not routinely recap, bend or break a used needle. Keep loose sharps out of rubbish, recycling and toilets; follow local disposal rules.
Why it matters Single-use means one injection, even if the same person will use the medicine again.
FDA sharps disposal guidance ↗
Know when to get help.
Contact your clinician about increasing redness, swelling, fever, persistent pain or bleeding that does not stop. Seek emergency care for trouble breathing, facial or throat swelling, or fainting. After an injury from someone else’s used needle, wash the area and obtain prompt medical attention.
Record the date, medicine, prescribed amount and site if your care team asks you to. Storage and discard instructions still apply even if the calculator shows additional theoretical portions.
Read the original guidance.
Sources checked October 6, 2026. Illustrations are original, simplified teaching diagrams. This page has not undergone independent clinical review.