When carrying out hormone injections, you'll need to use the correct needle size and follow safe disposal practices. We're going to take you through the different needle gauges, the steps for making an injection, and how to dispose of your needle afterwards.
Needle and Syringe Basics
Different needle gauges and lengths are used depending on injection site and type:
| Green needle gauge | Blue needle gauge | Orange needle gauge |
|---|---|---|
 |  |  |
| Size: 21G, ~0.8 mm × 40 mm | Size: 23G, ~0.6 mm × 25 mm | Size: 25G, ~0.5 mm × 16 mm |
| Often used for intramuscular (into the muscle) injections in the buttock. | Common for intramuscular injections in the thigh. | Used for subcutaneous injections (less common for testosterone). |
When preparing your injection, you should first use a blunt, filtered needle to draw the medication from the ampoule or vial. Before injecting, always replace it with a new hypodermic (injection) needle. Never inject with the same needle you used to draw up the medication.
Always use a new sterile needle and syringe each time – do not reuse needles.
If you're not sure how to use your injectible medicine, you can book an Injection Session with us to get help from a professional.
How to Inject Safely
Wash your hands and prepare a clean area.
Check your medication's expiry date.
Use a blunt, filtered needle to draw medicine from ampoules or vials.
Replace the drawing-up needle with a fresh injection (hypodermic) needle before injecting.
Clean the skin at the injection site with alcohol.
Insert the needle at a 90° angle in one smooth movement.
Inject slowly and steadily.
Withdraw the needle and press gently on the site with clean gauze or cotton.
For more information on your specific medication, see the Taking Medication section of the Knowledge Base.
Where to Buy Needles and Syringes in the UK
You can obtain needles and syringes from any reputable medical supply sources. Always ensure you are choosing the correct size for your medication and the injection site.
Some options include:
Medical supply companies: these often stock a range of sterile needles, syringes, and accessories.
Pharmacies or surgical suppliers: local pharmacies may stock or be able to order what you need (sterile hypodermic needles).
Online specialist medical equipment retailers: many UK-based online medical supply shops deliver to your address (check for proper certification and hygiene standards).
Before purchasing, you should confirm the correct gauge and length for your prescribed medication and injection site.
How to Get and Use a Sharps Bin
Getting a Sharps Bin
You can obtain a sharps bin by:
Asking during your next consultation with us.
Ordering from medical supply companies. Sharps bins are commonly available in different sizes.
Contacting your local council. Some UK local authorities provide free collection or replacement sharps bin services. You should check your council's website to see whether this is available in your area.
If your GP prescribes for you, they’ll be able to help you with this.
If possible, plan ahead so you always have a sharps bin available before your next injection.
Disposing Used Needles
Immediately after use, place the used needle and syringe parts into a sharps bin.
Do not recap the needle – avoid any attempt to re-sheath it.
When the sharps bin is full (according to its marked fill level), follow your local council's guidelines for collection or drop-off. Never throw full sharps bins into household waste.