Testosterone Replacement Therapy (TRT) injections are a common medical procedure prescribed to treat conditions like hypogonadism. While a healthcare provider can administer the injection, many patients are trained to perform self-administration at home. Self-injection must only be done after receiving comprehensive training and approval from a medical professional. This information is intended to provide general context and is not a replacement for personalized medical advice or hands-on training from your prescribing physician. You must strictly follow the specific dosage, frequency, and injection route provided in your prescription plan.
Essential Supplies and Preparation
Gather the correct, sterile materials, including the prescribed testosterone medication (such as cypionate or enanthate). The prescription details the necessary syringes and needles. These often include a larger gauge needle (like 18-gauge) for drawing the thick, oil-based medication from the vial and a smaller gauge needle (like 23- to 25-gauge) for the injection.
You will also need sterile alcohol pads to clean the medication vial top and the injection site. A designated, puncture-proof sharps disposal container is essential for safety. Wash your hands thoroughly with soap and water before handling any supplies. Wipe the vial’s rubber stopper with an alcohol pad and let it air-dry completely before use.
Selecting and Preparing the Injection Site
Testosterone injections are administered using two primary methods: intramuscular (IM) or subcutaneous (SubQ), as specified by your doctor. IM injections deliver medication deep into muscle tissue, with common sites being the gluteal muscle (buttocks) or the vastus lateralis (thigh). SubQ injections deliver medication into the fatty layer beneath the skin, offering a more gradual release.
Common SubQ sites include the abdomen (at least one inch away from the belly button) and the upper third of the thigh. The choice between IM and SubQ depends on the prescribed volume, comfort level, and desired absorption profile. Regardless of the site chosen, cleanse the area with a fresh alcohol pad and allow the skin to dry fully before proceeding, as injecting through wet skin can cause stinging.
Step-by-Step Injection Technique
Drawing the Dose
Drawing the prescribed dose begins by pulling air into the syringe equivalent to the dose volume. Insert the drawing needle through the vial’s stopper, invert the vial, and inject the air to equalize pressure, which aids in pulling out the viscous, oil-based testosterone. Pull the plunger back to draw the precise amount of medication, ensuring the needle tip remains submerged to avoid drawing air.
After drawing the medication, remove the needle from the vial and check the syringe for air bubbles. Gently flick the barrel to help trapped bubbles rise, then push the plunger slightly to expel only the air. If required by your protocol, replace the drawing needle with the smaller, sterile injection needle to minimize discomfort.
Injecting the Medication
Hold the syringe like a dart and insert the needle smoothly and quickly into the prepared site. For IM injections, insert the needle straight in at a 90-degree angle. For SubQ injections, the angle is typically 45 degrees (if pinching one inch of skin) or 90 degrees (if pinching two inches). Once inserted, slowly depress the plunger to inject the medication at a controlled, steady pace.
Wait a moment after the slow injection is complete to ensure the medication has dispersed, then withdraw the needle quickly at the insertion angle. If you experience shooting pain or severe burning, stop immediately and contact your healthcare provider, as this may indicate a nerve or blood vessel has been struck. Follow your physician’s specific instructions regarding aspiration (checking for blood), though many modern protocols no longer require it.
Post-Injection Care and Safety
Immediately after withdrawing the needle, apply gentle pressure to the injection site with a sterile gauze pad or cotton ball. Avoid rubbing the area, as this can increase irritation, bruising, or medication leakage. A small amount of bleeding or a minor bruise is a common reaction, and you may apply a small bandage if needed.
The most important safety step is the immediate and proper disposal of the used needle and syringe. Do not recap, bend, or break the needle; place the entire used assembly into the sharps container without delay. Once the container is full, seal it and take it to an approved disposal site, such as a pharmacy or medical office, to prevent injury or contamination.
Monitor the injection site for adverse reactions over the next few days. Mild soreness or tenderness is normal. Seek immediate medical attention if you notice severe pain, excessive swelling, warmth, persistent redness, or pus, as these indicate infection. Be aware of systemic symptoms like chest pain, difficulty breathing, severe dizziness, or signs of an allergic reaction, which require emergency care.