Testosterone replacement therapy (TRT) has gone from obscure endocrinology topic to mainstream conversation. Clinics are everywhere. Influencers are promoting it. And a lot of men are jumping on it prematurely while others who genuinely need it are avoiding it out of fear.
Let's cut through both the hype and the stigma with what the evidence actually shows.
When TRT Is Medically Indicated
Clinical hypogonadism requires both:
- Low testosterone levels — typically total T below 300 ng/dL on two separate morning blood draws
- Symptoms — fatigue, reduced libido, erectile dysfunction, depression, decreased muscle mass, increased body fat, cognitive decline, low motivation
Having low T without symptoms, or symptoms without low T, doesn't meet the diagnostic threshold. This matters because testosterone fluctuates with sleep, stress, diet, and time of day. A single low reading after a bad night of sleep isn't diagnostic.
Primary hypogonadism (testicular failure): the testes can't produce enough testosterone. Causes include Klinefelter syndrome, injury, mumps orchitis, chemotherapy, or age-related decline.
Secondary hypogonadism (pituitary/hypothalamic): the signal from the brain is insufficient. Causes include pituitary tumors, obesity (aromatase in fat tissue converts T to estrogen, which suppresses GnRH), opioid use, head trauma, or idiopathic.
The distinction matters because secondary hypogonadism is often reversible by treating the underlying cause (lose weight, stop opioids, fix sleep) — while primary hypogonadism typically requires TRT.
Before Considering TRT: Optimize First
For men with total T between 300-500 ng/dL and symptoms, optimizing the following can often raise testosterone 100-200+ ng/dL:
Sleep: Testosterone is produced primarily during sleep. Sleeping 5 hours instead of 8 reduces testosterone by 10-15%. Fix this first.
Body composition: Every 1-point increase in BMI is associated with a 2% decrease in testosterone. Visceral fat contains aromatase, converting testosterone to estradiol. Losing 20 lbs of fat can raise T by 100+ ng/dL.
Resistance training: Regular heavy compound lifts (squats, deadlifts, presses) acutely elevate testosterone and chronically improve hormonal milieu. 3-4x/week minimum.
Nutrition: Adequate dietary fat (25-35% of calories), sufficient zinc (30mg/day), vitamin D (optimize to 50-70 ng/mL), magnesium (400mg/day), and adequate calories (severe restriction tanks T).
Stress management: Chronic cortisol elevation suppresses GnRH and LH, directly reducing testosterone production.
Supplements with evidence:
- Tongkat ali (200-400mg/day) — may increase free T by reducing SHBG
- Ashwagandha (600mg/day) — cortisol reduction indirectly supports T
- Zinc (30mg/day) — restores T in deficient individuals
- D-aspartic acid (2-3g/day) — modest short-term T increase, unclear long-term benefit
- Boron (6-10mg/day) — may reduce SHBG and increase free T
If total T remains below 300 ng/dL after 3-6 months of genuine optimization, TRT becomes a rational conversation.
TRT Protocols
Testosterone cypionate (most common in US): 100-200mg/week intramuscular or subcutaneous injection. Half-life ~8 days.
Protocol optimization:
- Frequency matters more than dose. 2-3 injections per week (e.g., 50mg every 3 days) produces more stable levels than 1x/week, reducing estrogen spikes and mood fluctuations.
- Subcutaneous injection is gaining preference — less painful, potentially smoother absorption, and validated in clinical studies.
- Starting dose: 100mg/week is reasonable. Titrate based on labs and symptoms at 6-8 week intervals.
Target levels: Total T of 700-1000 ng/dL (mid-to-upper normal range). Free T in the upper quartile of reference range. Supraphysiological levels (>1100 ng/dL) increase cardiovascular risk without proportional benefit.
Other delivery methods:
- Testosterone gel (AndroGel, Testim): 1-2% applied daily. Risk of transfer to partners/children through skin contact.
- Testosterone pellets (Testopel): subcutaneous implants lasting 3-6 months. Convenient but dose adjustment is impossible once implanted.
- Testosterone undecanoate (Nebido): long-acting injection every 10-14 weeks. Stable levels but difficult to adjust.
Ancillary Medications
HCG (Human Chorionic Gonadotropin): 250-500 IU 2-3x/week alongside testosterone. Maintains intratesticular testosterone production, preserves testicular volume, and supports fertility. Essential if fertility preservation is important.
Aromatase Inhibitors (anastrozole): 0.25-0.5mg 2-3x/week if estradiol rises above 40-50 pg/mL. Use judiciously — crashing estradiol causes joint pain, mood issues, and cardiovascular risk. Many men on reasonable TRT doses don't need an AI at all, especially with more frequent injection protocols.
DHEA (25-50mg/day): Exogenous testosterone can suppress adrenal androgen production. DHEA supplementation maintains the broader hormonal milieu.
Monitoring Protocol
Baseline labs (before starting):
- Total and free testosterone (2 separate morning draws)
- Estradiol (sensitive assay)
- SHBG
- LH and FSH (to determine primary vs secondary)
- CBC (hematocrit/hemoglobin baseline)
- Comprehensive metabolic panel
- Lipid panel
- PSA (prostate baseline)
Follow-up labs (6-8 weeks after dose change, then every 3-6 months):
- Total and free testosterone (trough — draw before next injection)
- Estradiol (sensitive)
- Hematocrit (most important safety marker — TRT stimulates erythropoiesis)
- PSA (annual minimum)
- Lipid panel (TRT can adversely affect HDL)
- Comprehensive metabolic panel
Red flags requiring action:
- Hematocrit >54% (donate blood or reduce dose — polycythemia increases stroke/clot risk)
- PSA rise >1.4 ng/mL/year or absolute >4.0 (prostate evaluation needed)
- Estradiol >50 pg/mL with symptoms (consider AI or increase injection frequency)
Risks and Side Effects
Established risks:
- Polycythemia (elevated red blood cells) — most common complication. Increases blood viscosity and clot risk.
- Infertility — exogenous testosterone suppresses sperm production. Often reversible with cessation + HCG, but not guaranteed.
- Testicular atrophy — without HCG, testes shrink from disuse. Cosmetic and potentially functional.
- Acne and oily skin — DHT-mediated. Usually manageable.
- Hair loss acceleration — in genetically predisposed individuals, TRT can accelerate male pattern baldness via increased DHT.
- Sleep apnea exacerbation — testosterone can worsen existing sleep apnea.
- Lipid changes — HDL typically decreases 10-20%. LDL may increase.
Contested risks:
- Cardiovascular disease — early studies suggested increased risk; more recent data (TRAVERSE trial, 2023) showed no increased cardiovascular events in men with hypogonadism on TRT over a mean 33-month follow-up. The picture is mixed, but TRT in truly hypogonadal men appears relatively safe cardiovascularly.
- Prostate cancer — TRT does not appear to cause prostate cancer, but it's contraindicated in men with active prostate cancer (T fuels existing tumors).
The Fertility Question
This deserves emphasis: TRT is a form of male contraception. Exogenous testosterone tells your brain to stop producing LH and FSH, which stops testicular sperm production.
For men wanting children:
- HCG monotherapy (1000-1500 IU 3x/week) can raise testosterone while preserving or improving fertility
- Clomiphene citrate (25-50mg/day or every other day) stimulates LH/FSH production, raising testosterone without suppressing spermatogenesis
- Enclomiphene (12.5-25mg/day) — the active isomer of clomiphene with fewer side effects
These alternatives raise testosterone 200-400 ng/dL in many men with secondary hypogonadism, without the fertility suppression of TRT.
The Commitment
TRT is, for most men, a lifelong decision. Stopping TRT after extended use (>1 year) often results in a prolonged period (months to years) of low testosterone while the HPTA (hypothalamic-pituitary-testicular axis) recovers — if it fully recovers at all.
This doesn't mean you can never stop. Post-cycle therapy protocols (HCG + clomiphene + time) can restart natural production. But it's not guaranteed, and the recovery period can be miserable.
Go into this decision with eyes open. It's not a supplement you can casually try and drop.
The Bottom Line
TRT is a legitimate medical intervention for men with confirmed hypogonadism who have exhausted lifestyle optimization. It can be life-changing — improved energy, mood, body composition, cognitive function, and quality of life.
But it's not a shortcut. Optimizing sleep, body composition, training, and nutrition should come first. If total T remains below 300 ng/dL after genuine optimization, find a knowledgeable endocrinologist or men's health clinic (not a testosterone mill that starts everyone at 200mg/week with an AI and calls it medicine).
Monitor your labs religiously. Use the minimum effective dose. Protect fertility if it matters to you. And understand that this is likely a lifelong commitment, not a quick fix.