- Use a new, sterile needle and syringe every time, and never share any equipment.
- The ventrogluteal (side of hip), thigh and shoulder are the standard intramuscular sites; each holds a different volume.
- Rotate sites to avoid scar tissue and soreness.
- Time of day doesn’t matter for long-acting esters; consistency does.
Injection technique is the most practical safety skill for anyone using injectable testosterone or other injectables, prescribed or not. Poor technique causes most of the infections, abscesses and nerve problems people associate with injecting. This guide walks through the steps nurses use, adapted for self-injection, plus where Canadians can get free supplies.
If you’re prescribed testosterone, ask your pharmacist or nurse to show you once. Many pharmacies in Canada will supervise your first self-injection.
Supplies
- A new syringe (usually 3 ml) and needles: one to draw, one to inject
- Alcohol swabs
- Gauze or a cotton ball and a bandage
- A sharps container
Needle size
For intramuscular injections, needles are typically 22 to 25 gauge (higher numbers are thinner) and 25 to 38 mm (1 to 1.5 inches) long. Thinner needles are more comfortable but slower for thick oils. Longer needles are needed for the glutes or for people with more body fat at the site. A larger needle (for example 18 to 21 gauge) is often used to draw oil from the vial, then swapped for the injection.
Choosing a site
| Site | Where | Typical max volume | Notes |
|---|---|---|---|
| Ventrogluteal | Side of the hip | 2 to 3 ml | Preferred by nurses: thick muscle, away from major nerves |
| Vastus lateralis | Outer middle thigh | 2 to 3 ml | Easiest to reach for self-injection |
| Deltoid | Upper outer shoulder | About 1 ml | Small muscle; keep volumes low |
| Dorsogluteal | Upper outer buttock | 2 to 3 ml | Near the sciatic nerve; harder to self-inject safely |
To find the thigh site, divide the outer thigh between hip and knee into thirds and use the middle third, on the outer side.
Step by step
- Wash your hands with soap and water and work on a clean surface.
- Check the vial: the oil should be clear, with no particles or cloudiness. If it’s crystallized from cold, warm it and swirl until clear.
- Swab the vial top with alcohol and let it dry.
- Draw: pull back air equal to the dose, push it into the vial, then draw the oil slowly. Remove air bubbles.
- Change needles to a fresh injection needle; drawing through the rubber stopper dulls the tip.
- Swab the site and let it dry fully, which also reduces stinging.
- Insert the needle at 90 degrees with a quick, steady motion.
- Aspiration (pulling back to check for blood) is no longer recommended for vaccines, but many still do it for oil-based injections. If you see blood, withdraw and start again with fresh equipment at a new site.
- Inject slowly, about 10 seconds per ml for oils, which reduces pain.
- Withdraw, press gauze on the site, and don’t rub hard.
- Dispose of the needle and syringe immediately in a sharps container. Don’t recap used needles.
Rotate your sites
Repeated injections in the same spot cause scar tissue, lumps and pain. Rotate between left and right and between muscles, and keep a simple log of where you last injected.
Does time of day matter?
For long esters like testosterone enanthate and cypionate, no. Blood levels change over days, not hours, so morning versus evening makes no measurable difference. What matters is a consistent schedule: the same days each week. For short esters like propionate, regular spacing matters more than the time on the clock.
Normal soreness vs warning signs
Some soreness for a day or two is common, especially with short esters. Seek medical care if you have:
- Pain, redness, heat or swelling that increases after 48 hours
- A hard, hot lump, pus, or red streaks spreading from the site
- Fever or chills
- Numbness, tingling or shooting pain down the leg
- A sudden coughing fit with chest tightness that doesn’t settle within a few minutes
Infections can become serious quickly. A walk-in clinic or emergency department can treat an abscess; delays make them worse.
Free supplies in Canada
Harm-reduction programs across Canada provide free sterile needles, syringes, swabs and sharps containers, with no questions about what they’re for. Public health units, community health centres and many pharmacies take part. Search your province’s harm reduction site locator or ask your local public health unit. We also sell syringes with orders. For disposal, see our sharps disposal guide.
Frequently asked questions
What size needle for testosterone injections?
Typically 22 to 25 gauge and 25 to 38 mm long for intramuscular injection, with a larger needle to draw oil from the vial.
What’s the best injection site for beginners?
The outer thigh is easiest to reach and see. The ventrogluteal site is preferred by nurses but takes practice to locate.
Should I aspirate before injecting?
It’s no longer recommended for vaccines, but many still aspirate for oil injections. If blood appears, start again with new equipment.
Is it better to inject testosterone in the morning?
For long esters, timing within the day doesn’t matter. Keep a consistent weekly schedule.
Can I reuse a needle?
No. Reused needles are dull and unsterile, raising the risk of infection and tissue damage.
Products mentioned in this guide
This article is general information for adults in Canada, not medical advice. Talk to a doctor or pharmacist before using any prescription drug, anabolic steroid or research compound, and get bloodwork done. If you’re in crisis, call or text 9-8-8 (Suicide Crisis Helpline) any time.
