Disclaimer: This article is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional before starting any injection therapy, changing your medication routine, or if you have any health concerns.

This guide covers subcutaneous (the layer of fat just below the skin) self-administration of testosterone at home -- the injection route most commonly self-administered using standard insulin syringes. Intramuscular (into the muscle beneath the fat) testosterone protocols use different, longer needles and typically benefit from in-person training with a clinician or nurse. If your prescriber has you on an IM protocol, speak to your pharmacy about appropriate supplies and technique -- we don't stock IM injection needles and this guide isn't written for IM administration.

This guide is general information, not a substitute for advice from your prescriber. If anything about your medication or technique is unclear, ring your prescribing doctor or call Healthdirect on 1800 022 222.

SubQ TRT injection supplies including insulin syringe, alcohol wipes, and vial
SubQ testosterone injection supplies: insulin syringe, alcohol wipes, and sharps container.

Supplies You Need for SubQ Testosterone

  • 1ml insulin syringe (31G 6mm) -- used to both draw the testosterone from the vial and inject it. A single syringe handles both steps for each dose.
  • Alcohol wipes -- one for the vial stopper, one for your injection site.
  • Sharps container -- a locking 1.8L Sharpsafe is right-sized for home TRT use. Dispose of your used syringe immediately after each injection.

Step-by-Step: SubQ Testosterone Injection

  1. Wash your hands thoroughly with soap and water.
  2. Wipe the rubber stopper on your testosterone vial with an alcohol wipe. Let it air-dry for 10 seconds.
  3. Pull the insulin syringe plunger back to draw air equal to your prescribed dose volume.
  4. Insert the 31G needle through the rubber stopper and gently push the air into the vial. This equalises pressure and helps the oil draw.
  5. Invert the vial. Keep the needle tip in the oil and slowly pull back the plunger to draw your prescribed dose. Fine needles draw oil slowly -- this is normal; don't force it.
  6. Tap the syringe gently to move any air bubbles to the top, then push them out carefully.
  7. Wipe your chosen injection site with a fresh alcohol wipe. Let it air-dry.
  8. Pinch up a fold of skin between your thumb and fingers -- this is especially important if you have low body fat, to keep the needle in subcutaneous tissue.
  9. Insert the needle at 90 degrees into the pinched skin fold.
  10. Slowly push the plunger to inject. Hold the needle in place for 5--10 seconds after injecting before withdrawing.
  11. Apply light pressure with a clean alcohol wipe if any fluid appears at the site.
  12. Dispose of the syringe in your sharps container immediately.

Why pinch-up matters

The 6mm needle on a standard insulin syringe is the right length for most adults. For lean individuals (low body fat on the abdomen or thigh), pinching up a skin fold ensures the medication deposits in subcutaneous fat rather than at the fat-muscle interface. Depot testosterone relies on SubQ release pharmacokinetics -- depositing too shallowly or too deeply can affect absorption.

A note on needle re-use

Use a fresh insulin syringe for every injection. Don't re-use the same syringe across multiple injections. Puncturing the vial stopper with a used, dulled needle increases the risk of coring (shearing tiny rubber fragments into the vial) and of injection discomfort.

Self-injection technique: one hand pinches a fold of abdomen skin while the other inserts an insulin syringe at 90 degrees

SubQ Testosterone Injection Sites

  • Abdomen -- 2 inches (5cm) from the navel. Rotate between left and right sides and vary the spot each week.
  • Upper outer thigh -- another option with enough subcutaneous fat in most people.
  • Love handles / flanks -- good option for some, especially if abdomen and thigh need rotation breaks.
  • Upper outer buttock (gluteal) -- works well for lean men whose thighs and abdomen don't carry enough fat for a comfortable subQ injection. The upper-outer quadrant has plenty of subcutaneous tissue and stays hidden under clothing. Reach across with the opposite hand or use a mirror.

Rotate sites each injection. Avoid injecting into the same spot twice in a row -- consistent site rotation prevents lipohypertrophy (hardened, fatty tissue build-up) which can affect absorption.

Injection Site Rotation for SubQ TRT

TRT is a long-term treatment, often lasting years or indefinitely. Site rotation is not optional. Repeated injection into the same spot causes scar tissue and lipodystrophy (hardened or lumpy tissue), which impairs medication absorption over time.

Rotate between multiple areas on the abdomen and thighs. Move at least 2-3cm from your last injection site within each area. A simple system: inject on the left side of the abdomen on one day, right side next time, left thigh after that, right thigh after that. By the time you return to the first site, it has had at least two weeks of rest.

For a detailed rotation guide, see our Injection Site Rotation guide.

Common Issues and Troubleshooting

Oil is slow to draw

Draw directly with your insulin syringe and expect it to take 30-60 seconds. Warming the vial in your hands for 2-3 minutes before drawing can also help, as the oil becomes less viscous at slightly warmer temperatures. Do not heat the vial with hot water or a microwave.

Small lump at injection site after SubQ

A small, pea-sized lump is common after SubQ testosterone injection because oil is absorbed more slowly from fat tissue than from muscle. The lump is the oil depot and will be absorbed over 1-3 days. It is not harmful. If lumps persist beyond a few days or are painful, talk to your doctor.

Bleeding after injection

A few drops of blood after withdrawing the needle is normal and happens when the needle nicks a small blood vessel. Apply gentle pressure for 30-60 seconds. It does not mean the injection failed or that you need to re-inject. If you experience significant bleeding or a growing haematoma, contact your doctor.

Post-injection pain

Mild soreness at the SubQ injection site for a day or two is occasionally reported, especially early in treatment. Injecting slowly, using a sharp needle (never reuse), and warming the vial to room temperature before injection all reduce discomfort. If pain is severe, worsening, or accompanied by redness, swelling, or warmth, seek medical advice to rule out infection. Urgent red flags: fever, spreading redness, fluctuant swelling (suggesting abscess), severe pain, or pus -- seek medical care promptly.

TRT requires ongoing monitoring. Your doctor should check your testosterone levels, haematocrit (to screen for polycythaemia), PSA, and other markers on a regular schedule. This article is about injection technique only -- it does not replace your monitoring plan.

When to call your prescriber

Most injections go smoothly - a small drop of blood or a brief sting are normal. The list below covers things that aren't normal and warrant a phone call to your prescriber:

  • Redness, warmth or pus at the injection site that develops over 24-72 hours
  • A hard lump that doesn't go away after a week, or one that's hot and tender
  • Fever, chills or feeling unwell after an injection
  • Any rash, hives or itching at or beyond the injection site (possible allergic reaction)
  • Signs of a severe allergic reaction - swelling of face or throat, difficulty breathing - call 000 immediately
  • You realise you injected from a vial that had been left out, was cloudy or contained particles

Frequently Asked Questions

What supplies do I need for SubQ TRT injections in Australia?

At minimum: insulin syringes, alcohol wipes, and a sharps container. For SubQ: insulin syringes (31G 6mm) and alcohol wipes -- one syringe for both drawing and injecting. All of these are available over the counter in Australia without a prescription. For IM testosterone injections, speak to your pharmacy -- IS does not stock IM-gauge needles.

Can I do TRT injections subcutaneously?

Yes. Subcutaneous testosterone injection is supported by clinical research and is prescribed by many Australian TRT doctors, particularly for lower-dose, more frequent protocols. SubQ injections are less painful, use finer needles, and may produce more stable blood levels. Discuss with your doctor whether SubQ is appropriate for your protocol.

How often do I need to inject?

This depends entirely on your prescription. Your doctor will determine the dose and frequency based on your blood work. Do not change your protocol without medical guidance.

Do I need a prescription for injection supplies in Australia?

No. Syringes, needles, and alcohol wipes are available without a prescription in Australia. You can purchase them online or from most pharmacies. The testosterone itself requires a prescription, but the injection supplies do not.

How do I dispose of used TRT needles?

Used needles must go in a sharps container, never in regular household waste. In Australia, you can obtain free sharps containers from many pharmacies and council offices, and return full containers to pharmacies or community sharps drop-off points. See our Syringe Disposal Guide for full details.

Disclaimer: This article is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional before starting any injection therapy, changing your medication routine, or if you have any health concerns.

Browse our full TRT injection supplies collection:

For IM testosterone injections, speak to your pharmacy -- IS does not stock IM-gauge needles.