How to do a subcutaneous injection

What is a subcutaneous injection?

A subcutaneous injection delivers medication into the layer of fat just under the skin. It is not a deep muscle injection — the needle is short and the process is straightforward once you have done it a few times.

Most GLP-1 medications come in pre-filled auto-injector pens, which are designed to make self-injection as simple as possible.

Injection sites

You can inject into three areas of your body:

1. Abdomen — at least 5 cm away from your belly button
2. Front of the thighs — the outer third of each thigh
3. Back of the upper arms — the fatty area at the back (easier with help or a mirror)

Rotate your injection site each week. Injecting into the same spot repeatedly can cause a lump of fatty tissue to build up (lipohypertrophy), which can affect how well the medication absorbs.

Step-by-step guide

Before you start:

• Wash your hands thoroughly with soap and water
• Take your pen out of the fridge 30 minutes before injecting — room temperature is more comfortable
• Check the pen label matches your prescribed medication and dose
• Check the expiry date
• Inspect the medication — it should be clear and colourless

The injection:

1. Clean the injection site with an alcohol swab and let it dry completely (wet skin stings)
2. Remove the pen cap
3. If your pen requires a new needle, attach it now and remove the inner and outer needle caps
4. Prime the pen if required (your pharmacist or prescriber will show you this on your specific pen)
5. Press the pen firmly against your skin at the chosen site
6. Press the injection button and hold it down until you hear/feel a click
7. Keep the pen pressed against your skin for 5–10 seconds after clicking
8. Remove the pen and dispose of the needle in a sharps container

After:

• You may see a small red dot or a tiny drop of blood — this is normal
• Mild itching or redness at the site is common and usually resolves within a day or two
• Do not rub the site after injecting

Common concerns

"I can see a small bubble in the pen" — this is normal and does not affect your dose.

"The injection stung" — letting the pen reach room temperature helps. Make sure the skin is fully dry after using an alcohol swab.

"I'm not sure I injected properly" — if you are unsure, do not inject a second dose. Contact your prescriber or pharmacist.

Sharps disposal

Never put used needles in a regular bin. Use a designated sharps container, available from your pharmacy. When full, return it to your pharmacy for safe disposal.

General information note

This guide provides general educational information. Always follow the specific instructions provided with your medication and by your prescriber or pharmacist. If you are unsure about any step, ask your pharmacist to walk you through your specific pen device.