Complete Guide

Testosterone Replacement Therapy: The Complete Guide

Everything you need to know about TRT—from recognizing symptoms of low testosterone to understanding treatment options, costs, and how to get started.

Last updated: January 2025 • 15 min read

Quick Takeaway

TRT can effectively treat low testosterone symptoms like fatigue, low libido, and muscle loss when levels fall below 300 ng/dL. Online TRT clinics make access easier, with all-inclusive pricing around $150-250/month including medication and monitoring. It's not a magic solution—it requires ongoing commitment, regular blood work, and comes with real trade-offs including potential fertility impacts.

What Is Testosterone Replacement Therapy?

Testosterone replacement therapy (TRT) is exactly what it sounds like: replacing testosterone that your body isn't producing enough of on its own. It's prescribed to treat hypogonadism—the medical term for when your testes don't produce adequate testosterone.

This isn't about getting testosterone levels to "superhuman" heights (that's steroid abuse, which is different). TRT aims to restore your levels to the normal physiological range—typically between 400-700 ng/dL for most treatment goals.

Signs You Might Have Low Testosterone

Low testosterone (often called "Low T") doesn't announce itself with a single obvious symptom. It's usually a combination of issues that creep up gradually. Here's what to look for:

Physical Symptoms

  • Fatigue that doesn't improve with rest
  • Decreased muscle mass despite exercise
  • Increased body fat, especially around the midsection
  • Reduced body and facial hair
  • Decreased bone density

Sexual & Mental Symptoms

  • Low libido and reduced interest in sex
  • Erectile dysfunction
  • Brain fog and difficulty concentrating
  • Depression or irritability
  • Poor sleep quality

Important Note

These symptoms overlap with many other conditions—thyroid issues, depression, sleep apnea, diabetes, and simple aging. Never self-diagnose. Blood work is required to confirm low testosterone before starting treatment.

Understanding Testosterone Levels

Let's cut through the confusion around testosterone numbers. Here's what the research and clinical guidelines actually say:

Level (ng/dL)ClassificationNotes
<250 ng/dLClearly LowStrong candidate for TRT; guidelines recommend treatment
250-350 ng/dLBorderline LowTreatment threshold per AUA guidelines (300 ng/dL cutoff)
350-500 ng/dLLow-NormalMay treat if symptomatic; consider optimization strategies first
500-800 ng/dLOptimal RangeTarget range for most TRT protocols
800-1000+ ng/dLHigh-NormalUpper end of reference range; some clinics target this

The Diagnostic Standard

Per AUA and Endocrine Society guidelines, diagnosis should be based on:

  • At least two morning blood tests showing low testosterone (levels are highest in the morning)
  • Symptoms consistent with low T—numbers alone aren't enough
  • Same lab, same assay—results can vary between labs
  • Testing both total and free testosterone—free T can be low even when total is normal

TRT Treatment Options

Testosterone comes in several forms. Each has trade-offs in terms of convenience, consistency, and side effects:

💉

Injections (Testosterone Cypionate/Enanthate)

The most common and cost-effective method. Self-administered intramuscularly or subcutaneously every 1-2 weeks.

Pros:
  • • Most affordable option
  • • Highly effective
  • • Flexible dosing
Cons:
  • • Peaks and troughs between doses
  • • Requires learning to inject
  • • Can cause injection site reactions
🧴

Topical Gels & Creams

Applied daily to skin (shoulders, upper arms, or inner thighs). Brands include AndroGel, Testim, and compounded creams.

Pros:
  • • No needles required
  • • More stable levels (daily application)
  • • Easy to adjust dose
Cons:
  • • Transfer risk to partners/children
  • • Must let dry before contact
  • • More expensive than injections
💊

Pellets (Testopel)

Small pellets implanted under the skin every 3-6 months in a quick office procedure.

Pros:
  • • Set it and forget it
  • • Very consistent levels
  • • No daily/weekly routine
Cons:
  • • Minor surgical procedure required
  • • Harder to adjust if levels too high
  • • Pellets can extrude
🩹

Patches (Androderm)

Applied nightly to clean, dry skin. Changed every 24 hours.

Pros:
  • • Mimics natural testosterone rhythm
  • • No injections
  • • Consistent daily levels
Cons:
  • • Skin irritation common
  • • Can fall off during activity
  • • Less commonly prescribed now

Benefits of TRT: What to Actually Expect

Let's be realistic. TRT can significantly improve quality of life for men with genuinely low testosterone, but it's not a miracle drug. Here's what the research shows:

Improved Energy & Mood

Many men report decreased fatigue and improved motivation within 3-6 weeks. Depression symptoms often improve, though TRT isn't a treatment for clinical depression.

Increased Muscle Mass & Strength

TRT combined with resistance training leads to meaningful muscle gains. Effect is most noticeable after 3-6 months.

Improved Libido & Sexual Function

Sexual desire typically improves within the first month. Erectile function may improve, though this depends on the underlying cause.

Better Body Composition

Modest decreases in body fat and increases in lean mass. Not a shortcut for weight loss—diet and exercise still matter.

Improved Bone Density

Long-term TRT can help maintain or improve bone mineral density, reducing fracture risk.

Risks & Side Effects: The Full Picture

TRT isn't without downsides. Here's what you should discuss with your doctor before starting:

Common Side Effects

  • Acne and oily skin — Especially in the first few months
  • Increased red blood cell count (polycythemia) — This is why regular blood monitoring is essential; levels too high can increase clot risk
  • Testicular shrinkage — Your body stops producing its own testosterone, so the testes shrink
  • Fluid retention — Some men experience mild swelling or weight gain from water retention
  • Sleep apnea worsening — Existing sleep apnea can worsen on TRT

Serious Considerations

  • Fertility impact — TRT suppresses sperm production, sometimes to zero. If you want children, discuss alternatives like hCG or clomiphene first.
  • Cardiovascular concerns — Research is mixed. Some studies show benefit, others show risk. Discuss your cardiovascular health profile with your doctor.
  • Prostate health — TRT doesn't cause prostate cancer, but it can accelerate existing cancer. PSA monitoring is standard.
  • Lifetime commitment — Once you start, your body relies on external testosterone. Stopping can be difficult.

Who Should NOT Use TRT

  • • Men with prostate or breast cancer
  • • Men actively trying to conceive (use alternatives)
  • • Untreated severe sleep apnea
  • • Hematocrit above 50% (high red blood cell count)
  • • Uncontrolled heart failure

How Much Does TRT Cost?

Cost varies significantly based on how you access treatment:

OptionMonthly CostWhat's Included
Online TRT Clinics$150-250/moConsultation, labs, medication, ongoing monitoring
Urologist + Insurance$30-100/moCopays for visits, labs, medication (if covered)
Testosterone Injections (generic)$30-60/moMedication only (Cypionate/Enanthate)
AndroGel (brand)$400-600/moRetail price without insurance
Comprehensive Men's Clinic$250-500/moFull optimization including additional hormones/peptides

Best value: Online TRT clinics offer all-inclusive pricing that's predictable and usually includes everything you need. Going through insurance can be cheaper but often involves more hoops and may not cover the medication itself.

Online TRT vs. Traditional Doctor: Which Is Better?

Online TRT Clinics

Telemedicine platforms specializing in hormone optimization. Examples: Fountain TRT, Marek Health, TRT Nation.

✓ Convenient—consultations from home
✓ Specialized in TRT (it's all they do)
✓ All-inclusive pricing
✓ Quick access—often prescribed in days
✗ No in-person exam
✗ Usually doesn't accept insurance

Traditional Doctor (Urologist/Endo)

In-person care through a urologist, endocrinologist, or primary care physician.

✓ Full physical examination
✓ Can identify other issues
✓ May use insurance
✓ Comprehensive medical history review
✗ Longer wait times for appointments
✗ Less TRT-specialized
✗ May be conservative with prescribing

What to Expect: The TRT Timeline

Week 1-2: Getting Started

Blood work, consultation, prescription. You may feel a subtle boost in mood/energy early, but this is often placebo—give it time.

Week 3-6: Early Changes

Libido often increases noticeably. Energy levels improve. Sleep may improve or worsen (varies by individual).

Month 2-3: Stabilization

Blood work to check levels. Dose adjustments if needed. Muscle and body composition changes begin. Most side effects that will occur have appeared.

Month 6+: Full Effects

Maximum benefits realized. Ongoing monitoring every 6-12 months. You'll know by now if TRT is working for you.

Alternatives to TRT

If you want to address low testosterone without committing to exogenous testosterone, there are alternatives:

  • Clomiphene (Clomid) — Stimulates your body to produce more testosterone naturally. Often used for men wanting to preserve fertility.
  • hCG (Human Chorionic Gonadotropin) — Stimulates the testes to produce testosterone. Sometimes used alongside TRT to maintain testicular function.
  • Lifestyle optimization — Better sleep, weight loss, strength training, and stress management can boost testosterone 10-30% in some men.
  • Enclomiphene — Newer, cleaner version of Clomid with fewer side effects.

The Bottom Line

TRT can be genuinely life-changing for men with clinically low testosterone. The fatigue lifts, motivation returns, and quality of life improves significantly.

But it's not a decision to take lightly. You're committing to:

  • Ongoing treatment (potentially for life)
  • Regular blood monitoring
  • Managing side effects
  • Cost ($150-250/month is realistic for most)

Best candidates: Men with confirmed low testosterone (<300 ng/dL on two tests), clear symptoms, no contraindications, and realistic expectations about what TRT can and can't do.

Find TRT Treatment

Choose telehealth convenience or find local hormone clinics with hands-on care.

Medical Disclaimer

This guide is for educational purposes only and does not constitute medical advice. Testosterone replacement therapy is a prescription treatment that should only be used under physician supervision. Individual results vary. Always consult with a qualified healthcare provider before starting TRT.