How to Inject Testosterone for TRT & Tirzepatide – Complete Guide
Mastering how to inject testosterone for TRT (oil-based) and water-based compounds like tirzepatide is key to comfortable, effective, and safe treatment. Proper technique—whether subcutaneous (subQ) or intramuscular (IM)—minimizes pain, lumps, irritation, and ensures consistent absorption.
At IncreaseMyT, we compound premium MCT oil-based testosterone and high-quality water-based solutions. Here’s your complete guide on how to inject testosterone for TRT and tirzepatide/peptides, including sites, needles, volumes, cleaning, and advanced methods.
Preparation: Cleaning Before You Inject Testosterone for TRT
Before any injection, prioritize hygiene to prevent infection.
- Clean the Vial: Wipe the rubber stopper thoroughly with an alcohol swab and let it air dry. A good clean wipe is sufficient.
- Clean the Site: Swab the injection site with alcohol in a circular motion, starting from the center outward. Let it air dry completely.
- General Tips: Wash your hands thoroughly, use fresh alcohol pads, and avoid touching the needle tip.
These steps are critical when learning how to inject testosterone for TRT or tirzepatide.
Subcutaneous Injections – How to Inject Testosterone for TRT (Oil-Based)
MCT oil-based testosterone flows easily through fine needles, making subQ the preferred method for twice-weekly TRT.
Use a 29-gauge insulin needle (5/16"–1/2" length) in these sites. Recommended maximum volumes:
- Abdomen: No more than 0.5 mL (50 units) per injection to minimize lumps.
- Deltoid (shoulder): 1–2 mL per injection.
- Quadriceps (thigh): 1–2 mL per injection.
- Abdomen: 3–4 inches outside the belly button (most popular). Firm the tissue without pinching. Insert the needle at a 45° angle for comfortable insertion. Do not inject too close to the belly button to avoid bruising.
- Deltoid (shoulder): Outer upper arm (center of deltoid). Stabilize the area. Insert straight in (perpendicular, 90° angle) — do not angle the needle.
- Quadriceps (thigh): Divide the quad into four quadrants. Use the upper outer quadrant only. Insert straight in (perpendicular, 90° angle) — do not angle. Injecting too low can cause lumps.
MCT oil reduces post-injection pain. Clean vial and site as described.
Quadriceps (thigh)
Subcutaneous Injections – Water-Based Compounds (Tirzepatide & Peptides)
Water-based compounds like tirzepatide absorb well subcutaneously with minimal discomfort.
Use a 31-gauge insulin needle (5/16" or 8mm length) and inject into the abdominal area, 3–4 inches outside the belly button.
- Site: Firm the tissue by pressing gently (no pinching). Do not inject too close to the belly button to avoid bruising.
- Technique: Insert the needle at a 45° angle, inject slowly, and hold for 5–10 seconds before withdrawing.
- Advantages: Very low pain, no aspiration needed, quick healing.
Intramuscular (IM) Injections – Oil-Based Testosterone for TRT
IM is effective for larger volumes or when subQ isn't preferred.
Use a 20-gauge needle to draw, then switch to a 25-gauge 1-inch needle for injection. Recommended maximum volumes:
- Deltoid: Up to 2 mL.
- Glutes (dorsogluteal): Up to 3 mL.
- Ventrogluteal: Up to 5 mL (preferred for larger doses).
Recommended sites:
- Deltoid: Upper outer shoulder—good for smaller volumes.
- Glutes (dorsogluteal): Upper outer quadrant (avoid sciatic nerve).
- Ventrogluteal: Safer glute site—hand on hip bone, form a "V" with fingers.
Technique: Insert at 90°, aspirate if directed (see below), inject slowly, massage gently.
On Aspiration: Many experts now recommend skipping routine aspiration due to increased pain without proven benefit. Consult your provider.
Deltoid
The Air Lock Method (Optional for Oil-Based Testosterone)
Draw a small air bubble (0.1–0.2 mL) after loading the dose. Inject the air last to push medication fully into tissue and reduce leakage.
- When to use: Helpful for IM oil-based testosterone if leakage occurs.
- Tip: Not needed for subQ or water-based compounds.
The Z-Track Method (Recommended for IM Oil-Based Testosterone)
Pull skin taut to one side, insert at 90°, inject, hold 10 seconds, withdraw, then release skin to seal the track.
- When to use: Ideal for glutes/ventrogluteal with oil-based testosterone to prevent leakage and irritation.
- Advantages: Reduces staining, leakage, and site reactions.
Quick Comparison of Injection Methods
Ready to Master How to Inject Testosterone for TRT?
With the right technique, injecting testosterone for TRT or tirzepatide becomes simple, safe, and effective.
Contact IncreaseMyT to discuss our PCAB-accredited formulations and get personalized guidance from your provider.
Always consult your physician before beginning or changing any therapy. This article is for informational purposes only and not medical advice.
