What Is TRT? A Physician’s Guide to Testosterone Replacement Therapy
By Dr. Luis Valle, DO
What Is Testosterone Replacement Therapy (TRT)?
Testosterone replacement therapy (commonly called TRT) is a physician-supervised treatment that restores testosterone levels in men (and occasionally women) whose bodies no longer produce adequate amounts.
It's not a steroid cycle. It's not bodybuilding enhancement. It's a medical intervention for a measurable hormonal deficiency that affects energy, cognition, body composition, mood, libido, and long-term health.
If you've heard of TRT through podcasts, social media, or locker room conversation, this guide is designed to separate the science from the noise.
Why Testosterone Declines
Testosterone production peaks in a man's late 20s to early 30s and declines approximately 1–2% per year after age 30. This is a normal physiological process, but “normal” doesn't mean “optimal.”
By age 45, many men have lost 15–30% of their peak testosterone. By 55, the decline is often clinically significant. Factors that accelerate this decline include:
- Chronic stress. Elevated cortisol suppresses testosterone production.
- Poor sleep. Testosterone is primarily produced during deep sleep.
- Excess body fat. Adipose tissue converts testosterone to estrogen via aromatase.
- Sedentary lifestyle. Resistance training stimulates testosterone; inactivity doesn't.
- Environmental factors. Endocrine disruptors in plastics, pesticides, and personal care products.
- Alcohol and substance use. Chronic alcohol consumption directly suppresses production.
Symptoms of Low Testosterone
Low testosterone (hypogonadism) manifests differently in each patient, but common symptoms include:
- Persistent fatigue that doesn't improve with adequate sleep
- Brain fog, difficulty concentrating, reduced mental sharpness
- Loss of muscle mass or difficulty building muscle despite training
- Increased body fat, especially abdominal and visceral fat
- Reduced libido and sexual function
- Mood changes: irritability, anxiety, low motivation, mild depression
- Slower recovery from exercise or injury
- Hair thinning or changes in hair quality
- Disturbed sleep patterns
- Reduced bone density (long-term)
The challenge: many of these symptoms overlap with other conditions (thyroid dysfunction, nutrient deficiencies, sleep disorders, depression). This is why a comprehensive blood panel, not just a testosterone test, is essential before starting TRT.
Checking more than a few boxes? Get a comprehensive hormone panel with Dr. Valle →
How TRT Works
TRT delivers exogenous testosterone to bring your levels back into the optimal range (typically 700–1,100 ng/dL, though “optimal” varies by patient). The goal is to restore what your body no longer produces sufficiently, not to achieve supraphysiological levels.
Delivery methods include:
| Method | Frequency | Pros | Cons |
|---|---|---|---|
| Intramuscular injection (cypionate) | Weekly or biweekly | Most common, reliable levels, cost-effective | Requires injection (self-injectable after training) |
| Subcutaneous injection | Weekly or biweekly | Less painful, self-injectable | Slightly less studied than IM |
| Topical gel/cream | Daily | No injections, steady levels | Skin transfer risk, daily application, variable absorption |
| Testosterone pellets | Every 3–6 months | Least frequent, consistent levels | In-office procedure, less adjustable |
Injectable testosterone (cypionate) is the most common protocol we prescribe, due to its reliability, cost-effectiveness, and ease of dose adjustment.
What to Expect on TRT
Weeks 1–4: Most patients notice improved energy and mood. Sleep quality often improves.
Weeks 4–8: Mental clarity sharpens. Libido typically improves. Patients report feeling “more like themselves.”
Weeks 8–16: Body composition changes begin: reduced fat, increased lean mass (especially with resistance training).
Months 4–6: Full optimization. Dr. Valle adjusts dosing based on follow-up labs and symptoms to fine-tune your protocol.
Ongoing: Most patients describe TRT as one of the highest-impact health decisions they've made. The key is ongoing monitoring to ensure levels stay optimal and side effects are managed.
Side Effects and Risks
TRT is safe when properly prescribed and monitored, but it's not without considerations:
- Erythrocytosis (elevated red blood cells). Monitored via CBC; managed with dose adjustment or therapeutic phlebotomy.
- Estrogen conversion. Testosterone can convert to estradiol via aromatase; monitored and managed with ancillary medications if needed.
- Fertility suppression. Exogenous testosterone reduces sperm production. Alternatives exist for men who want to preserve fertility (hCG, clomiphene).
- Acne or oily skin. Typically mild and manageable.
- Testicular atrophy. Expected with exogenous testosterone; reversible if TRT is discontinued. hCG can be used to maintain testicular size.
This is why physician supervision matters. A qualified physician monitors your labs, adjusts your protocol, and manages side effects proactively, not reactively.
TRT vs. Telehealth: What's the Difference?
Telehealth TRT providers have made testosterone more accessible. That's a positive development. But accessibility has trade-offs: no in-person physical exam, basic lab panels that often miss key markers, rotating providers who don't know your history, and no combined services.
For patients who want a real physician relationship (someone who reads your full labs, performs a physical exam, and connects hormone optimization to your overall health), in-person TRT with a dedicated physician practice is the standard.
Want TRT managed by a physician who knows your name? Book a consultation at True Roots →
How Much Does TRT Cost?
| Component | Typical Range |
|---|---|
| Initial consultation + comprehensive labs | $200–400 |
| Monthly testosterone (a la carte) | $150–350/mo |
| Monthly TRT as part of a membership | $200–400/mo (includes additional services) |
| Quarterly follow-up labs | $75–200 |
Our PERFORMANCE membership ($449/mo) lets you pick a Treatment Track: OPTIMIZE (TRT management), RESTORE (Folix), or REFINE (NAD+ 250mg IV). All tracks include quarterly labs, Botox at $12/unit, and 20% off everything else. For most TRT patients, the OPTIMIZE track is the most cost-effective and comprehensive option.
See the full membership breakdown and what's included. Compare membership tiers →
Is TRT Right for You?
TRT is appropriate for men with documented low testosterone (confirmed by blood testing) who are experiencing symptoms. It is not appropriate for men with normal testosterone levels, active prostate cancer, uncontrolled polycythemia, or certain other conditions.
The only way to know is to test. A comprehensive blood panel gives us the data to make an informed recommendation, not a guess.
Next Steps
If you're experiencing symptoms of low testosterone and you're in the La Cañada Flintridge, Pasadena, or greater Los Angeles area:
- Book a consultation with Dr. Valle at True Roots
- Get comprehensive bloodwork (not just a total testosterone test)
- Review your results with a physician who will explain what's optimal, not just what's “normal”
- Start a protocol (if TRT is appropriate) with ongoing monitoring and integrated care
Frequently Asked Questions
TRT is a physician-supervised treatment that restores testosterone levels in men whose bodies no longer produce adequate amounts. It is a medical intervention for a measurable hormonal deficiency that affects energy, cognition, body composition, mood, and libido.
TRT typically costs $150–350 per month for medication, plus $200–400 for the initial consultation and labs, and $75–200 for quarterly follow-up labs. Membership programs at physician practices often bundle TRT with additional services at $200–400 per month.
When prescribed and monitored by a qualified physician, TRT has a strong safety profile. Potential side effects include elevated red blood cells, estrogen conversion, and fertility suppression, all managed through regular lab monitoring and protocol adjustments.
Most patients notice improved energy and mood within 2–4 weeks. Body composition changes typically become visible at 8–12 weeks. Full optimization often takes 3–6 months with protocol adjustments.
About the Author
Dr. Luis Valle is a board-certified physician and co-founder of True Roots in La Cañada Flintridge, CA. He prescribes and monitors TRT, peptide therapy, and hormone optimization protocols as part of a comprehensive performance and aesthetics practice.
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$250 gets you a 30+ marker blood panel, a one-on-one with Dr. Valle, and a treatment plan built on your data. Applies as a credit toward your first treatment if you proceed.