How do I give myself an intramuscular testosterone injection?
Intramuscular (IM) testosterone goes deep into a large muscle, and for self-injection the best site is the outer middle third of the thigh (the vastus lateralis). You use two needles for one injection: a 20G x 1" needle to draw the thick oil out of the vial, then a fresh 22G or 23G needle, 1" to 1.5" long, to inject. Stretch the skin to one side (the Z-track), go in at 90 degrees, check briefly for blood, push slowly, and drop the syringe straight into a sharps container. Skip the old upper-outer buttock shot on yourself; it sits too close to the sciatic nerve.
In more than two decades of practicing medicine, I have taught this injection to more patients than I can count. Intramuscular is the route testosterone cypionate and enanthate were approved for, and it has the longest track record. Done right, it is quick and uneventful. Done casually, it is where the bruises, sore legs, and nerve scares come from. Here is the technique, exactly as we teach it in the office.
Written by Dr. Ty Tallman, NMD, Integrative Medical Partners, Mesa, AZ. Updated November 2, 2026.
What you will need
| Item | What it is for |
|---|---|
| 1 cc or 3 cc syringe | Holds the volume. We dispense the size that fits your amount. |
| 20G x 1" needle | Drawing needle. Wide bore pulls the viscous oil out of the vial quickly. |
| 22G or 23G needle, 1" to 1.5" | Injection needle. Long enough to pass through the fat and reach muscle, not bone. We choose the length for your body at your teaching visit. |
| Alcohol pads | The vial stopper and the skin. Two separate pads. |
| Gauze or cotton ball | Light pressure afterward. |
| Bandage | Only if the site bleeds. |
| Sharps container | Disposal. Never household trash. |
| Your medication vial | Dispensed from our office, labeled with your name and your amount. |
Your amount is individualized and set by our office. We mark your syringe line for you at your teaching visit. Never adjust it on your own, and never borrow someone else’s vial or instructions.
Where to inject: the four sites, ranked for self-injection
| Site | Where it is | Our take |
|---|---|---|
| Outer thigh (vastus lateralis) | Outer side of the thigh, middle third, between the hip bone and the knee | Best for self-injection. Easy to see and reach, no major nerves or vessels in the target zone. |
| Side of the hip (ventrogluteal) | Hand on the hip, injection in the V between the index and middle fingers | Anatomically the safest site, but hard to reach on yourself. Ideal when a partner gives the injection. |
| Shoulder (deltoid) | About 2 to 3 finger-widths below the bony point of the shoulder | Small volumes only. Inject too high and you can injure the shoulder joint. Ask us before using it. |
| Upper-outer buttock (dorsogluteal) | The classic “back pocket” shot | Avoid for self-injection. The sciatic nerve runs close by, and you cannot see what you are doing. |
Alternate between your right and left thigh each injection, and move a little within the zone each time. Stay away from skin that is bruised, tender, red, hard, or scarred.
Step by step: drawing up
- Wash your hands. Lay out the syringe, both needles, two alcohol pads, gauze, and the sharps container.
- Inspect the vial. The oil should be clear and free of floating particles. Check the expiration date and that the seal is intact. If it looks cloudy or has visible specks, do not use it — call us.
- Flip off the plastic cap on a new vial. Wipe the rubber stopper with alcohol and let it dry.
- Attach the 20G x 1" needle to the syringe.
- Pull the plunger back to your marked line, drawing in that much air.
- Push the needle through the center of the stopper and inject the air into the vial. This equalizes pressure so the oil comes out instead of fighting you.
- Turn the vial upside down, keep the needle tip in the oil, and pull slowly to your line.
- Tap the barrel so bubbles rise, push them back into the vial, and recheck your line. Oil holds bubbles more stubbornly than water, so be patient here.
- Withdraw the needle, remove the 20G, and attach a fresh injection needle. Do not squirt oil out to prime it — that is your medication.
Step by step: giving the injection
- Sit down and relax the leg. A tensed muscle hurts more. Find the outer middle third of the thigh.
- Clean the skin with the second alcohol pad in an outward circle and let it dry completely. Wet alcohol stings.
- Z-track the skin. With your free hand, pull the skin about an inch to one side and hold it there. When you let go afterward, the track closes over and seals the oil in, which means less leakage, less bruising, and less soreness.
- Insert at 90 degrees with one quick, confident, dart-like motion. Do not pinch the skin up; that is the subcutaneous technique.
- Aspirate briefly. Pull back gently on the plunger for about 5 to 10 seconds. Thick oil through a fine needle shows blood slowly, so give it a moment. If blood appears, stop — see “If something goes wrong” below.
- Push slowly and steadily. Oil into muscle takes time; thirty seconds or more is fine and more comfortable.
- Wait about 10 seconds, then withdraw straight out and release the skin.
- Press lightly with gauze. Do not rub or massage the site. Bandage only if it bleeds.
- Drop the whole syringe into the sharps container. Do not recap, do not reuse, one needle per injection.
If something goes wrong
| What you notice | What to do |
|---|---|
| Mild soreness, a little swelling or bruising | Common and usually settles in 1 to 3 days. A cold compress helps. Not a reason to stop therapy. |
| Blood in the syringe when you aspirate | Stop. Withdraw, apply pressure, and discard that syringe. Start over with a fresh draw and a new needle at a new spot, and let us know. |
| Shooting pain, numbness, tingling, or weakness down the leg or arm | Stop injecting right away. Text or call us the same day. |
| Redness, warmth, or pain that spreads and worsens over days, pus, a soft fluctuant lump, or fever | Possible infection. Contact us the same day. |
| Severe pain at the site right after injecting, followed by blotchy, purple, or darkening skin | Rare, but urgent. Seek care immediately. |
| Sudden coughing, urge to cough, chest tightness, or shortness of breath within minutes of the injection | Rare oil-related reaction. If breathing is hard, call 911. If it passes quickly, still tell us before your next injection. |
| Hives with trouble breathing, throat tightness, faintness, or vomiting | Possible allergic reaction. Call 911 now. |
Intramuscular or subcutaneous? The honest comparison
- IM is the approved route. Standard testosterone cypionate and enanthate vials are labeled for intramuscular use, and IM has decades of data behind it.
- IM handles larger volumes. Muscle accepts more oil per injection than the fat layer comfortably does.
- The tradeoff is the curve. In a comparative study, intramuscular cypionate was associated with higher post-therapy estradiol and hematocrit than subcutaneous enanthate, with no difference in achieved total testosterone or PSA.
- And the needle. A longer, wider needle into muscle is more likely to leave you sore than a short one into fat.
Neither route is wrong. The right one is the one you will actually do, done well, with labs that confirm it is working. If IM is not sitting well with you, here is how the subcutaneous technique works, and we can talk about switching.
When to call us
- Anything in the table above beyond mild soreness.
- You are not sure you got the full amount in. Do not repeat the injection. Text us.
- Any of the class-wide effects we monitor for: a rising hematocrit, a bump in blood pressure, or new swelling.
- Your labs are due. Testosterone therapy is a measured therapy, not a set-and-forget one. Trough timing matters for interpretation, so keep your draw on schedule.
Common questions
Do I need to aspirate before injecting?
For intramuscular oil, we teach a brief aspiration. Aspiration is no longer recommended for vaccines, but oil-based depot injections are a different situation, and a few seconds of checking is cheap insurance against putting oil into a vessel.
Why the thigh and not the buttock?
You can see your thigh. The upper-outer buttock sits near the sciatic nerve, and injecting it blind by reaching behind yourself is where nerve injuries happen. If someone else is giving the shot, the side of the hip (ventrogluteal) is excellent.
How long should the needle be?
Long enough to get through the fat into muscle, not so long it reaches bone. For most adult thighs that is 1" to 1.5"; patients with more tissue over the muscle may need the longer length. We set this for you in person.
My leg is sore the next day. Is that normal?
Mild soreness for a day or two is common with IM oil. A relaxed leg, the Z-track, a slow push, and no massage all help. Soreness that grows instead of fading is worth a text.
I coughed right after my injection. Should I worry?
A sudden cough or tight chest within minutes of an oil injection is uncommon but known. If you are struggling to breathe, call 911. If it passed quickly, tell us before your next injection so we can review technique and the plan.
Can I switch from IM to subcutaneous?
Often, yes. Many patients do. It is a conversation, not a do-it-yourself change, because the needle, the site, and how we read your labs all shift with it.
Related reading: subcutaneous testosterone injection, step by step, why testosterone raises your hematocrit and what we do about it, testosterone therapy and fertility, and how pellets compare if you would rather not inject at all. Your first injection should never be a guess. We teach the technique in the office, mark your syringe, and follow up on how it is going.
Text us at 480-219-2624 to schedule, or call. Quick response, real scheduling, no phone tree. 1910 S Stapley Dr #120, Mesa, AZ 85204.
To Health and Wellness, Dr. Ty Tallman
References
- Journal of Psychiatric and Mental Health Nursing, 2008 — review of best practice for intramuscular injections
- Journal of Advanced Nursing, 2000 — drawing up and administering intramuscular injections
- Journal of Advanced Nursing, 2004 — preventing sciatic nerve injury from intramuscular injections
- Journal of Advanced Nursing, 2023 — clinical practice recommendations for intramuscular injections, modified Delphi study
- Red Book (American Academy of Pediatrics), 2024 — injection administration and treatment of anaphylactic reactions
- JAMA Pediatrics, 2017 — pain and skin necrosis following intramuscular injection
- The Journal of Urology, 2022 — outcomes with intramuscular cypionate versus subcutaneous enanthate in hypogonadal men
- Clinical Endocrinology, 2022 — Society for Endocrinology guidelines for testosterone replacement therapy in male hypogonadism
- JAMA, 2026 — adult male hypogonadism review