How to Inject Testosterone: Injection Sites and Technique
Testosterone replacement therapy (TRT) often means giving yourself a shot every week or two. Choosing the right site, needle, and routine keeps levels steady and helps you avoid lumps, bruising, and wasted medication.
Most adults on prescription testosterone can inject safely at home by placing the hormone into a large muscle (intramuscular, IM) or the fatty layer just under the skin (subcutaneous, SubQ). The top IM sites are the outer thigh and upper outer glute, while SubQ shots usually go into the belly or thigh. Use a fresh, appropriately sized needle, rotate locations, and follow the training your licensed provider gives you-never a friend or online video alone.
- Intramuscular testosterone is typically delivered with a 22- or 23-gauge, 1- to 1.5-inch needle into the vastus lateralis (outer thigh) or dorsogluteal/ventrogluteal hip muscle (dailymed.nlm.nih.gov).
- Subcutaneous injections use a smaller 25- to 27-gauge, ½- to ⅝-inch needle placed at a 90-degree angle into pinched abdominal or thigh fat, which many patients find less painful (Arora et al., 2018).
- Rotating sites-moving at least one inch from the last spot-reduces the risk of scarring, oil buildup, and nodules, and helps the hormone absorb evenly.
- Never reuse needles and never share syringes; used syringes can carry hepatitis C or other infections in up to 13 % of samples collected at needle-exchange programs (Bergström et al., 2024).
- Call your provider right away for severe pain, swelling larger than a golf ball, a fever over 100.4 °F, or shortness of breath after a shot.
What testosterone injections do
Testosterone injections replace the hormone your testes are no longer producing at healthy levels. The medication-most often testosterone cypionate or enanthate-is suspended in oil and released slowly over days after it is deposited into muscle or fat. FDA labeling for intramuscular testosterone cypionate lists dosing ranges of 50–400 mg every 2–4 weeks (dailymed.nlm.nih.gov), but your licensed provider individualizes the amount and schedule.
IM vs SubQ absorption: Intramuscular injections create a higher early peak, while weekly SubQ shots maintain a flatter, steadier curve that many patients prefer (Arora et al., 2018). Both routes reach physiologic male testosterone levels when done correctly and monitored with blood work.
Rx.com is launching TRT from Rx.com (coming soon), an at-home testosterone cypionate program prescribed online by U.S.-licensed providers and shipped to your door once approved.
Best places to inject
Choose a site with enough depth-muscle for IM, pinchable fat for SubQ-and few large nerves or vessels.
| Route | Primary Sites | Landmarks | Pros | Watch-outs |
|---|---|---|---|---|
| Intramuscular (IM) | Outer thigh (vastus lateralis), upper outer glute (ventrogluteal or dorsogluteal), deltoid* | Mid-thigh between hip and knee; glute: palm on greater trochanter, fingers toward iliac crest | Large muscle mass, slower leak-back | Need longer needle; awkward to reach glute alone |
| Subcutaneous (SubQ) | Abdomen (2 inches from navel), outer thigh, love-handle area | Pinch at least ¾ inch of fat | Smaller needle, often less pain, easy to self-access | Oil can form tiny lumps if site not rotated |
| *Deltoid is acceptable for trained users with adequate muscle, but avoid deltoid for first-timers or large volumes. | ||||
Why rotation matters: Repeatedly hitting the exact same spot can cause scar tissue, delayed absorption, or a sterile abscess. Move at least one inch in a circular pattern and alternate left/right sides each time.
Supplies you’ll need
Your provider or pharmacy supplies most of these at prescription pick-up or shipment.
- Syringe (usually 1 mL or 3 mL Luer-Lock)
- Drawing needle (18- or 20-gauge, 1.5 inch) and injection needle (see table below)
- Vial of testosterone cypionate or enanthate
- Alcohol prep pads and gauze
- Hard-sided FDA-cleared sharps container
- Small adhesive bandage (optional)
| Route | Typical Needle Gauge | Needle Length | Maximum Volume per Shot |
|---|---|---|---|
| IM | 22-23 G | 1–1.5 inches | Up to 3 mL |
| SubQ | 25-27 G | ½: ⅝ inch | Up to 1 mL |
| Sources: FDA drug label; Endocrine Society guideline. | |||
Step-by-step technique
Follow the training your licensed provider gives you; these steps are a refresher, not a substitute for in-person instruction.
- Wash your hands with soap and warm water for 20 seconds.
- Draw up the dose: Attach the large drawing needle, pull air equal to the dose, inject air into vial, invert, and slowly draw oil to the mark. Tap bubbles to the top and push them out.
- Switch to the injection needle without touching the hub. Recap safely using one-hand “scoop” or a needle change device.
- Prepare the skin: Wipe the site with an alcohol pad in a 2-inch circle; let it dry completely.
- Insert the needle:
- IM: Stretch skin taut, insert quickly at 90 ° to muscle.
- SubQ: Pinch a fold of fat, insert at 90 ° (or 45 ° if the needle is long for your fat depth).
- Inject slowly: Depress plunger over 5-10 seconds per mL to reduce tissue pressure.
- Withdraw and compress: Withdraw along the same line; apply gauze with gentle pressure for 10 seconds. Massage is not needed.
- Dispose of needles immediately into the sharps container.
- Log the site and dose in your tracking app or paper log.
Studies of a pre-filled subcutaneous autoinjector found an 80 % first-attempt success rate-even in people new to injections-when they followed the instructions for use (Arora et al., 2018).
Want a simpler way to stay on schedule?
Rx.com is launching convenient at-home TRT from Rx.com (coming soon) with supplies shipped to your door once prescribed.
How to rotate sites
Rotation prevents tissue damage and keeps absorption predictable. A simple four-quadrant grid on your thigh or abdomen works well. Move clockwise each week and note the exact location in your log. If you notice lingering soreness, skip that area for at least two cycles.
Maximum per site volumes: Experts cap IM injections at 3 mL and SubQ at 1 mL; larger volumes increase post-shot leakage and nodules (JCEM review).
Should I inject into muscle or fat today?
Check the column that fits your situation:
✅ SubQ is a good option if
- You have at least ¾ inch of pinchable fat at the site
- Your weekly dose is 1 mL or less
- You prefer a smaller needle and less injection pain
- Your provider has reviewed your labs and okayed SubQ
🏥 Stick with IM or call your provider if
- You inject more than 1 mL per dose
- Your body fat is very low and you cannot pinch skin
- You recently had surgery or infection near the site
- You notice large lumps, redness, or warmth after SubQ shots
Safe sharps disposal
Used needles go straight into a sturdy, leak-proof sharps container-never the trash. When the container is three-quarters full, seal it and follow your state or local program for drop-off or mail-back. Most pharmacies, hospitals, or household hazardous-waste sites take filled containers. Never recap or clip a used needle; more than 80 % of accidental sticks happen during recapping (cdc.gov).
🚨 When to Contact Your Healthcare Provider
Contact your doctor immediately if you experience any of the following:
- Fever over 100.4 °F: may signal injection-site infection
- Shooting pain, numbness, or tingling around the site, could indicate nerve injury
- Rapid swelling or a hard lump larger than a golf ball that worsens over 24 hours
- Shortness of breath or chest pain soon after an injection, which requires emergency evaluation
- Vision changes, severe headache, or dizziness-possible high hematocrit or blood pressure spike (high hematocrit on TRT)
- Signs of an allergic reaction such as rash, hives, or throat swelling
- Mood changes, depression, or suicidal thoughts; call or text the 988 Suicide & Crisis Lifeline 24/7 if you feel unsafe
Troubleshooting and pro tips
Warming the vial: Rolling the vial between your palms for 30 seconds thins the oil and makes it easier to draw.
Changing needles after drawing up: Pulling thick oil dulls the tip; swapping to a fresh needle prevents tissue drag and pain.
Slow, steady injection: A 5- to 10-second push per mL reduces pressure and leakage back along the track.
Stay still: Flexing the muscle during an IM shot hurts. Relax your leg or hip completely.
Document everything: Date, time, site, dose, and even lot number make it easy to troubleshoot later with your provider or pharmacist.
Need more background on treatment? See how telehealth treats low testosterone and how testosterone optimization starts online.
Scientific References
- Arora S, Moclair B, Murphy K, et al. Summative Usability Evaluation of the SCTE-AI Device: A Novel Prefilled Autoinjector for Subcutaneous Testosterone Administration. J Sex Med. 2018.
- Bergström MA, Andersson ME, Larsson SB. Detection of drugs and hepatitis C virus in used syringes from a needle exchange in Gothenburg, Sweden. Drug Test Anal. 2024.
- DailyMed. dailymed.nlm.nih.gov.
- Just a moment. academic.oup.com.
- Sharps Safety Program Resources | Infection Control | CDC. cdc.gov.
Frequently Asked Questions
What size needle should I use for testosterone shots?
For intramuscular injections most providers recommend a 22- or 23-gauge needle 1- to 1.5 inches long. For SubQ shots a 25- to 27-gauge needle ½ - ⅝ inch is typical. Your exact size depends on body composition and dose.
Is a SubQ injection as effective as an intramuscular shot?
Yes. Clinical studies and an FDA-cleared autoinjector show weekly SubQ testosterone achieves stable, normal male levels with excellent patient satisfaction (Arora et al., 2018). Blood work confirms whether levels remain in range.
Can I split my dose into two smaller injections?
Some clinicians have patients divide one weekly IM dose into two smaller SubQ shots to reduce peaks and side effects. Only adjust timing or amount if your prescribing provider instructs you to do so.
Do I have to aspirate before pushing the plunger?
Current guidelines do not require aspiration for SubQ injections. For IM shots, many providers still teach a brief pull-back; follow the specific technique your trainer demonstrated.
What if I see blood in the syringe after I insert the needle?
Withdraw, discard the syringe, and start over in a new location. A small surface capillary was likely pierced. Injecting testosterone directly into a blood vessel can cause cough or dizziness.
How should I store my testosterone vial?
Store at controlled room temperature (68-77 °F). Avoid direct light and do not refrigerate-cold oil thickens and is harder to draw up.
Does insurance cover sharps containers?
Many plans consider them a medical supply and cover a basic container; call the number on your card. If not, pharmacies sell approved containers for $5-10, and some municipalities provide them free.
Ready for easier, monitored TRT at home?
Rx.com is launching online testosterone replacement therapy soon. Join the waitlist to see if TRT from Rx.com is right for you-licensed providers, prescription cypionate, and supplies shipped straight to your door.
