What Happens During Testosterone Replacement Therapy: Your First TRT Session

Before Your Appointment

Schedule your appointment for mid-morning when testosterone levels are naturally highest, providing the most accurate baseline readings. Fast for 9-12 hours beforehand if lipid profiles are being checked alongside hormone levels, though you can drink water normally.

Wear comfortable clothing with easy access to your upper arm for blood draws. If you're starting with injections, loose-fitting trousers will make accessing injection sites more comfortable. Bring a complete list of current medications, supplements, and any previous hormone test results—these help your clinician understand your hormone history and identify potential interactions.

Avoid intense exercise for 24 hours before blood work, as this can temporarily alter hormone levels. Similarly, limit alcohol consumption for 48 hours prior to testing, as alcohol can suppress testosterone production and skew results.

The Initial Consultation

Your first appointment typically lasts 45-60 minutes and begins with comprehensive blood work. The phlebotomist will draw several vials to test total testosterone, free testosterone, luteinising hormone, follicle-stimulating hormone, oestradiol, and safety markers like PSA and haematocrit. The needle pinch lasts only seconds, followed by gentle pressure and a plaster.

Next comes a detailed medical history covering symptoms like fatigue patterns, sleep quality, mood changes, and sexual function. Your clinician will perform a physical examination including blood pressure, heart rate, and assessment of secondary sexual characteristics. They'll also examine the prostate through digital rectal examination—this takes less than 30 seconds and, while briefly uncomfortable, provides crucial safety information.

If you're a suitable candidate and choose to proceed, your clinician will demonstrate injection techniques using a practice model. Most patients receive training on intramuscular injections into the thigh or gluteal muscle, using needles that are surprisingly thin—many describe the sensation as similar to a routine vaccination.

Your First Injection Experience

Whether administered by your clinician or self-injected under supervision, the actual injection process is typically straightforward. After cleaning the injection site with alcohol, you'll feel a brief sharp sensation as the needle penetrates the skin, followed by mild pressure as the testosterone solution is slowly injected over 10-15 seconds.

The injection site may feel slightly tender for a few hours afterwards—similar to post-vaccination soreness. Some patients notice a metallic taste immediately after injection, which resolves within minutes. If you're learning self-injection, your clinician will observe your technique and provide feedback to ensure proper administration.

For gel preparations, your first application involves spreading a measured amount across clean, dry skin on your shoulders, upper arms, or abdomen. The gel absorbs within 30 minutes, leaving no visible residue. Your clinician will emphasise the importance of washing hands thoroughly afterwards and covering the application area with clothing to prevent transfer to others.

Immediate Aftercare and Early Expectations

Leave the injection site uncovered to air dry, avoiding tight clothing that might irritate the area for the first few hours. Apply a cold compress if soreness develops, but avoid heat which can increase inflammation. For gel users, wait at least four hours before swimming or showering to ensure proper absorption.

Don't expect immediate changes—testosterone replacement works gradually. Some men notice improved energy and mood within the first two weeks, but most significant changes occur over 6-12 weeks. Sleep quality often improves first, followed by increased motivation and gradually enhanced libido. Physical changes like increased muscle mass typically require 3-6 months of consistent treatment.

Contact your clinic immediately if you experience chest pain, difficulty breathing, or signs of allergic reaction. Mild injection site reactions, temporary mood fluctuations, or changes in urination frequency are common initially and usually resolve as your body adjusts to treatment.

Treatment Schedule and Long-term Monitoring

Most men receive injections every 1-2 weeks, though some prefer longer-acting preparations administered monthly or quarterly. Gel applications are daily, typically applied each morning after showering. Your clinician will adjust dosing based on follow-up blood work at 6-8 weeks, then every 3-6 months once levels stabilise.

Regular monitoring appointments involve blood tests to check testosterone levels, haematocrit, PSA, and liver function. These visits typically last 15-20 minutes and provide opportunities to discuss any side effects or dosing adjustments. Many patients find their symptoms significantly improve within three months, though individual responses vary considerably.

TRT is generally a long-term commitment—stopping treatment typically results in testosterone levels returning to pre-treatment ranges within weeks. Most men continue therapy indefinitely once they experience benefits, making the relationship with your supervising clinician particularly important for ongoing safety and effectiveness monitoring.