Testosterone Replacement Therapy: Definition in Plain Language — 3 Delivery Methods, 1 Lab Requirement

Testosterone replacement therapy is a physician-managed protocol that restores testosterone levels in men with clinically confirmed hypogonadism, using measured hormone supplementation to address symptoms of fatigue, low libido, cognitive decline, and muscle loss.

What Testosterone Replacement Therapy Is

Testosterone replacement therapy (TRT) addresses a defined medical condition: hypogonadism, the failure of the testes to produce adequate testosterone, whether through primary (testicular) or secondary (hypothalamic-pituitary) failure, or through age-related andropause that reduces testosterone production by approximately 1% to 2% per year after age 30.

TRT requires lab confirmation before it is prescribed. The 1 non-negotiable lab requirement at Rebuild Regen is: 2 morning fasting total testosterone panels below the clinical threshold, interpreted alongside free testosterone, SHBG, LH, FSH, and a complete metabolic panel. Symptoms without lab confirmation are not sufficient for TRT initiation.

The 3 delivery methods for TRT are: intramuscular or subcutaneous injection (weekly or biweekly), subcutaneous pellet therapy (every 4 to 6 months), and topical gel or cream (daily).

How TRT Works

Testosterone replacement therapy supplements the body's endogenous testosterone production to restore levels to the physiological male range, typically targeting 600 to 900 ng/dL total testosterone. Testosterone binds androgen receptors throughout the body to drive protein synthesis in muscle, regulate red blood cell production, support bone density, maintain libido and erectile function, and support cognitive function and mood.

TRT does not restore natural testicular testosterone production. Exogenous testosterone suppresses LH and FSH through negative feedback, which reduces sperm production. Men with fertility goals require a different approach (clomiphene, hCG) or must weigh the fertility implications before starting TRT.

How Rebuild Regen Delivers TRT

Testosterone replacement therapy at Rebuild Regen Medical Clinic at 3320 N Federal Hwy #101, Lighthouse Point, FL is managed by Elizabeth Celestin, APRN, FNP-C with full monitoring labs at 4 to 6 weeks and every 6 months. Pellet insertion is performed in-office under local anesthetic. Self-injection training is provided for injection protocols. The monitoring protocol includes hematocrit, PSA, estradiol, and testosterone levels at every interval.

See the complete TRT guide for full protocol details.

Is TRT the Right Option for Your Situation?

TRT is appropriate for men with 2 confirmed morning fasting testosterone panels below the clinical threshold, with symptoms consistent with deficiency. Other causes of the same symptoms (thyroid, sleep apnea, depression, metabolic issues) are excluded by the complete lab panel before TRT is recommended.

Risks and Limitations of TRT

TRT is contraindicated in prostate cancer, erythrocytosis, severe untreated sleep apnea, and active pregnancy intent without a managed stimulation protocol. Long-term TRT suppresses natural testosterone production; most men who begin TRT continue long-term. PSA monitoring is a routine part of the protocol for prostate safety.