Bloodwork Basics for Testosterone Replacement Therapy: Key Labs, Target Ranges, and Monitoring Schedule
Introduction
Testosterone replacement therapy can restore energy, libido and muscle mass, but it’s not a set‑and‑forget solution. TRT affects multiple body systems and requires careful monitoring to ensure safety and effectiveness. The cornerstone of this monitoring is bloodwork. Comprehensive lab testing before and during therapy helps identify the underlying cause of low testosterone, tailor dosing, detect side effects early and optimize overall health.
Baseline Evaluation
Before starting TRT, your healthcare provider should order a comprehensive panel of blood tests. Two morning testosterone tests — drawn between 7 a.m. and 10 a.m. — are necessary to confirm low levels. Because testosterone fluctuates daily, repeating the test ensures accuracy. Baseline labs should include:
Total and free testosterone. Total testosterone includes hormone bound to proteins; free testosterone measures the biologically active portion.
Sex hormone–binding globulin (SHBG). Determines how much testosterone is bound versus free.
Estradiol (E2). Men convert some testosterone to estrogen; monitoring E2 helps prevent excessive conversion.
Luteinizing hormone (LH) and follicle‑stimulating hormone (FSH). Evaluate pituitary function; low LH/FSH with low testosterone may indicate secondary hypogonadism.
DHEA and DHEA‑sulfate. Precursors to sex hormones; low levels may indicate adrenal insufficiency.
Complete blood count (CBC). Includes hemoglobin and hematocrit to establish baseline red blood cell levels.
Comprehensive metabolic panel (CMP). Assesses liver (AST, ALT) and kidney (creatinine, BUN) function and electrolytes.
Lipid profile. Measures cholesterol (LDL, HDL) and triglycerides; TRT can affect lipids.
Fasting glucose and insulin or HbA1c. Detects insulin resistance and diabetes.
Prostate-specific antigen (PSA). Men should have a baseline PSA to screen for prostate issues.
Thyroid panel. Includes TSH, free T4 and free T3; thyroid disorders can mimic or contribute to low T.
Other markers. Depending on your history, your provider may order prolactin (to rule out pituitary tumors), cortisol (for adrenal health), IGF‑1 (growth hormone status), inflammatory markers (CRP, homocysteine) or vitamin D.
For women considering low‑dose testosterone therapy, baseline labs also include estradiol, progesterone, and sometimes sex hormone metabolites to ensure balance. Because there is no universally accepted female testosterone deficiency threshold, clinical judgment is key.
Target Ranges
Target ranges help guide dosing but should be individualized based on symptoms and overall health.
Men:
Total testosterone: A typical reference range is 300–1,000 ng/dL. On TRT, many providers aim for a mid‑normal range of 500–800 ng/dL to relieve symptoms without overshooting.
Free testosterone: Optimal values often fall between 15–25 pg/mL, but this varies by lab. It’s important to interpret free testosterone relative to SHBG.
Estradiol (men): Keep E2 between 20–40 pg/mL. Elevated estradiol may lead to water retention, gynecomastia or mood changes; low estradiol can cause joint pain and low libido.
Hematocrit: Should remain below 54 % to avoid polycythemia and increased clot risk. If your hematocrit exceeds this threshold, your provider may lower your dose or recommend therapeutic phlebotomy.
PSA: Baseline and subsequent PSA values should be interpreted by your provider. A rapid rise may warrant urology referral.
Women:
Total testosterone: Typical female range is 15–70 ng/dL. On low‑dose therapy, aim to stay within or slightly above this range depending on symptoms.
Free testosterone: Usually 0.3–2 pg/mL, though optimal levels are individualized. Dosing must be conservative to avoid virilizing side effects.
Estradiol and progesterone: These hormones should remain balanced relative to testosterone. In post‑menopausal women, adding bioidentical estrogen and progesterone may be necessary.
Hematocrit: Women naturally have lower hematocrit than men; values should remain below 48 %.
Monitoring Schedule
Pre‑therapy:
Complete baseline labs listed above. Address any abnormalities (e.g., elevated liver enzymes, uncontrolled diabetes) before starting TRT.
6 weeks after starting TRT:
Check total and free testosterone to evaluate whether levels are in the desired range.
Measure estradiol to ensure it’s not rising excessively.
Repeat CBC to monitor hemoglobin and hematocrit.
For men, repeat PSA if baseline was elevated.
3 months:
Repeat hormone panel (testosterone, free T, E2, SHBG).
CBC, CMP, lipid profile and fasting glucose/insulin or HbA1c to assess metabolic effects.
PSA for men.
Every 3–6 months thereafter:
Continue monitoring testosterone, estradiol, hematocrit, PSA (men), liver enzymes and lipids.
Adjust dosing based on symptoms and results.
Assess blood pressure, weight, waist circumference and body composition at each visit.
Annually:
Consider a DEXA scan to evaluate bone density, especially if you had low bone density at baseline or are on long‑term therapy.
Repeat sleep study if you have sleep apnea or develop symptoms such as snoring and daytime sleepiness.
Perform comprehensive wellness evaluation, including cardiovascular risk assessment.
Interpreting Results
High hematocrit (>54 % in men, >48 % in women): This can thicken blood and increase clot risk. Your provider may reduce your dose, switch the route of administration or schedule therapeutic phlebotomy.
High estradiol: Elevated E2 can cause water retention, mood swings and breast tissue growth in men. Reducing testosterone dose or prescribing an aromatase inhibitor may be necessary. For women, high E2 relative to progesterone can cause weight gain, anxiety or breast tenderness.
High PSA: An increase in PSA doesn’t necessarily mean prostate cancer, but it warrants further evaluation. Your provider may refer you to a urologist for a digital rectal exam and imaging.
Elevated liver enzymes: TRT may impact liver function; persistent elevations may require dose adjustment or investigation into other causes (e.g., fatty liver, medications). Topical formulations often have less impact on liver enzymes than oral testosterone.
Low LH/FSH: On TRT, these pituitary hormones are suppressed because exogenous testosterone triggers negative feedback. This is expected; however, if you plan to have children, discuss fertility‑preserving options (such as hCG therapy) before starting TRT.
Women’s considerations: Women must watch for signs of virilization (acne, hair growth, deepening voice). If testosterone or DHEA levels become too high, reduce the dose or discontinue therapy. Monitor lipid profiles and blood pressure regularly.
Conclusion
Comprehensive bloodwork is the backbone of safe and effective testosterone replacement therapy. Knowing which tests to order, what the target ranges are and how often to repeat labs empowers you to advocate for your health and work collaboratively with your provider. If you’re considering TRT or are already on therapy but unsure about your monitoring schedule, Total Health Pros can help. Our clinic in Hurricane, WV offers thorough evaluations, evidence‑based treatment and ongoing support to ensure your hormone journey is safe and successful. Contact us today to schedule your lab review and take control of your hormonal health.
