Before You Begin
Testosterone replacement therapy (TRT) injections are administered intramuscularly (IM), which means the medication is injected deep into muscle tissue. This guide provides step-by-step instructions for safe self-administration. If you have questions about your prescribed dose or technique, contact your Impact Health provider before injecting.
- Prescribed testosterone vial (testosterone cypionate or enanthate)
- New syringe with needle (typically 22G–25G, 1"–1.5" length for IM injection)
- Alcohol wipes (for vial top and injection site)
- Sharps container or puncture-safe disposal bag
- Clean cotton pad or sterile gauze
- Bandage (optional)
Step-by-Step TRT Injection Tutorial
1. Prepare
Wash hands thoroughly with soap and warm water. Gather all supplies on a clean surface. If your testosterone is stored in the refrigerator, allow it to reach room temperature (about 15-20 minutes) before drawing. This makes it easier to draw and inject.
2. Inspect & Clean
Confirm the vial contains testosterone, check the concentration (mg/mL), and verify the expiration date. Wipe the rubber stopper on the vial with an alcohol pad and let it air-dry completely. Inspect your injection site for any redness, irritation, or broken skin.
3. Draw Your Dose
Remove the syringe cap. Pull back the plunger to draw air equal to your dose volume. Insert the needle through the rubber stopper and inject the air into the vial (this prevents vacuum). Invert the vial and slowly draw back until you reach your prescribed dose.
4. Remove Air Bubbles
Tap the syringe gently so air bubbles rise to the top. Push the plunger slightly to expel air until a small drop appears at the needle tip. Check that you have the correct dose. Do not recap the needle until you're ready to inject.
5. Prepare Injection Site
Clean the injection site with an alcohol wipe using a circular motion from the center outward. Let it air-dry completely (about 30 seconds). Do not touch the cleaned area before injecting. Rotate sites to avoid repeated injections in the same location.
6. Inject Intramuscularly
Stretch the skin taut (don't pinch). Insert the needle at a 90° angle (straight in) quickly and smoothly. Once fully inserted, pull back slightly on the plunger to check for blood (aspiration). If blood appears, withdraw and choose a new site. If no blood, inject slowly and steadily.
7. Withdraw & Aftercare
After injecting all medication, withdraw the needle in one smooth motion at the same angle. Apply gentle pressure with a sterile pad for 10-30 seconds. Do not rub the area. Apply a bandage if needed. Dispose of the syringe immediately in a sharps container.
8. Document
Record the injection date, time, site location, and dose in your tracking log. This helps you rotate sites properly and provides important information for your provider during follow-up visits.
Intramuscular Injection Sites for TRT
Testosterone is injected into large muscle groups. Rotate between these sites to prevent scar tissue buildup and ensure consistent absorption.
- Ventrogluteal (Upper Glute): Located in the upper outer quadrant of the buttock. This is often the preferred site as it has fewer nerves and blood vessels. Best accessed while lying on your side.
- Deltoid (Shoulder): Upper arm muscle. Easy to access but smaller muscle, so use appropriate needle length (1" typically).
- Vastus Lateralis (Outer Thigh): Upper outer portion of the thigh. Easy to access and visualize. Good for self-injection.
- Use a 90° angle (perpendicular to the skin) - do not angle like SubQ injections
- Stretch the skin taut rather than pinching (pinching is for SubQ)
- Insert quickly to minimize discomfort
- Aspirate (pull back slightly) to check for blood before injecting
- Inject slowly and steadily (about 10-15 seconds)
- Rotate sites each week to prevent tissue damage
TRT-Specific Safety Guidance
When to Call Your Provider
- Significant pain, swelling, or redness at injection site that persists more than 24-48 hours
- Signs of infection: warmth, pus, fever, or spreading redness
- Accidental injection into a blood vessel (you'll know if blood appears when aspirating)
- Uncertain about dose, vial appearance, or expiration date
- Missed injection or need to adjust schedule
- Any unusual symptoms or side effects
Storage & Handling
- Store testosterone vials at room temperature (unless your specific formulation requires refrigeration - check your pharmacy label)
- Protect from light and keep in original container
- Keep away from children and pets
- Do not use if the solution appears cloudy, discolored, or contains particles
- Discard expired vials safely - do not inject expired medication
Common TRT Injection Schedule
- Weekly injections: Most common schedule (e.g., every Monday or every Friday)
- Bi-weekly: Every 2 weeks (less common, may cause more peaks and valleys)
- Twice weekly: Some protocols use smaller doses twice per week for more stable levels
- Follow your provider's specific schedule - consistency is important for optimal results
Site Rotation Schedule
Rotating injection sites prevents scar tissue buildup, ensures consistent absorption, and reduces discomfort. Keep a simple log to track your rotation.
- Week 1: Left ventrogluteal (upper glute)
- Week 2: Right ventrogluteal (upper glute)
- Week 3: Left vastus lateralis (outer thigh)
- Week 4: Right vastus lateralis (outer thigh)
- Then repeat the cycle
Tip: You can also alternate between deltoids if preferred, but the glute and thigh sites are generally preferred for larger volume injections.
