Testosterone Replacement Therapy for Men — The Complete Guide

By age 35, most men have been losing testosterone at 1–2% per year. By 45, many are functionally hypogonadal — but their labs say “normal.” That’s because the reference range for total testosterone is roughly 264–916 ng/dL, a range so wide it includes both 25-year-old athletes and 80-year-old men with chronic disease.

Your doctor looks at your 340 ng/dL, sees it falls “within range,” and tells you you’re fine. You’re not. You’re fatigued, gaining visceral fat, losing muscle, sleeping poorly, thinking through fog, and watching your drive — in every sense of the word — disappear.

This isn’t a normal part of aging. It’s a treatable hormonal condition. And treating it correctly requires more than a testosterone prescription.

Why Most TRT Is Done Wrong

Here’s the typical TRT experience at a men’s health clinic or telehealth provider: You take a basic blood test. They check total testosterone. It’s low. They prescribe testosterone cypionate. Maybe they check in after a few months. Maybe they don’t.

The problems with this approach are significant. Total testosterone alone tells you almost nothing actionable. You need the full cascade: free testosterone, SHBG (sex hormone-binding globulin), estradiol via sensitive assay, DHT, LH, FSH, prolactin, DHEA-S, pregnenolone, and IGF-1. Without these, you’re optimizing blind.

Beyond that, testosterone doesn’t exist in isolation. It aromatizes to estradiol. It converts to DHT. It’s bound by SHBG. Your thyroid affects it. Your cortisol affects it. Your insulin sensitivity affects it. A proper TRT protocol accounts for all of these variables — not just the one number.

What We Test at Longitude Life

Every male patient receives a comprehensive hormone panel as part of their DECODE diagnostic workup:

Primary Hormones: Total Testosterone, Free Testosterone (equilibrium dialysis), SHBG, Estradiol (sensitive LC/MS), DHT, Pregnenolone, DHEA-S

Pituitary Axis: LH, FSH, Prolactin

Growth Hormone Axis: IGF-1

Thyroid (Complete): TSH, Free T3, Free T4, Reverse T3, Thyroid Antibodies

Metabolic Context: Fasting Insulin, HOMA-IR, HbA1c, hsCRP, CBC with differential, PSA, Comprehensive Metabolic Panel, Lipid Panel (advanced)

This isn’t a upsell — it’s the minimum required to design a protocol that actually works and doesn’t create new problems.

How We Treat

Testosterone ReplacementWe primarily use testosterone cypionate — injectable (intramuscular or subcutaneous), dosed weekly or biweekly based on your pharmacokinetics and labs. Some patients prefer compounded testosterone cream for daily topical application. Dosing is individualized based on your bloodwork, symptoms, SHBG levels, and response — never a cookie-cutter protocol.

Estrogen ManagementWhen testosterone is supplemented, some converts to estradiol via the aromatase enzyme. Elevated estradiol causes water retention, mood instability, and gynecomastia. We monitor estradiol with the sensitive assay every 90 days and use anastrozole only when clinically indicated — not reflexively.

Fertility PreservationTRT suppresses natural testosterone production and can reduce sperm count. For men who want to preserve fertility, we use enclomiphene citrate or hCG therapy to maintain testicular function and spermatogenesis. This is discussed before any protocol begins.

Supportive OptimizationDepending on your labs, your protocol may include DHEA supplementation, pregnenolone support, thyroid optimization, and peptide therapy. CJC-1295/Ipamorelin supports growth hormone output. BPC-157 accelerates tissue repair. PT-141 addresses sexual health directly through central melanocortin pathways.

What to Expect (Timeline)

Weeks 1–3: Subtle mood and energy improvement. Sleep quality often improves first.

Weeks 4–8: Noticeable increase in energy, mental clarity, and libido. Exercise recovery improves. Anxiety often decreases.

Months 3–4: Significant body composition changes — reduced visceral fat, increased lean mass. Lab values typically reach optimal ranges. This is where the first reassessment happens.

Month 6+: Full protocol maturity. Maximum benefits to muscle mass, cognitive function, sexual health, and mood stability. Bone density improvements measurable over time.

Monitoring: The Part Most Clinics Skip

At Longitude Life, your labs are re-run at 6 weeks, 12 weeks, and then quarterly. Every reassessment checks not just your testosterone — but your hematocrit (elevated red blood cells are the most common TRT side effect), PSA, liver function, lipid panel, estradiol, and metabolic markers. Your protocol is adjusted at every cycle based on data.

This is the SUSTAIN pillar in action. Set-and-forget TRT is negligent TRT.

Who Shouldn’t Start TRT

TRT is contraindicated in men with untreated prostate cancer, male breast cancer, uncontrolled erythrocytosis, severe untreated sleep apnea, or active desire for fertility without concurrent fertility preservation. These are evaluated during your initial consultation.

The Longitude Life Difference

We don’t just prescribe testosterone. We map your entire hormonal architecture, design a protocol that accounts for every variable, dispense your medications from our in-house formulary (included in your monthly medication credit), and reassess every 90 days. Your TRT is part of a larger system — DECODE your biology, RESTORE what’s broken, OPTIMIZE your performance, and SUSTAIN it for decades.

Both the Precision Protocol ($499/month with $200 medication credit) and the Longitude Protocol ($899/month with $300 medication credit) include comprehensive hormone management.

Your hormones aren’t optional. They’re infrastructure. → Schedule Your Evaluation