What is the standard TRT blood work schedule?
A typical TRT blood work schedule follows a predictable cadence: a comprehensive baseline panel before starting therapy, a follow-up panel around 6 weeks after starting (or after any dose change), a 3-month panel, a 6-month panel, then annually once levels and symptoms are stable. Hematocrit and PSA follow their own intervals — baseline, 3 to 6 months, 12 months, then annually — per the 2018 Endocrine Society clinical practice guideline (Bhasin S et al., Journal of Clinical Endocrinology & Metabolism) and the 2018 AUA Evaluation and Management of Testosterone Deficiency guideline (Mulhall JP et al.).
That schedule is the framework. The interesting part — and the part that drives most bad decisions on TRT — is which labs get ordered, when the draw happens relative to the dose, and how each marker is interpreted in context. This guide walks through each step, with the marker-by-marker thresholds prescribers actually watch.
For the pillar overview of every lab on a TRT panel, start with our complete TRT blood work guide. For the two markers that change the most on therapy, see estradiol on TRT and hematocrit on TRT.
Educational disclaimer — please read: This article is educational content, not medical advice. It is not a substitute for evaluation by a licensed physician who knows your full history. Lab schedules, target ranges, and dose decisions are clinical judgments that depend on your individual labs, symptoms, comorbidities, and medications. Do not change your testosterone dose, injection frequency, or any prescription based on this article. Always discuss changes with your prescriber. If you have chest pain, shortness of breath, severe headaches, vision changes, breast tissue changes, or suicidal thoughts, seek medical care immediately.
Why a structured TRT blood work schedule matters
The single most common reason a TRT protocol fails is not the dose. It is unstructured monitoring — labs drawn at the wrong time, the wrong markers ordered, or the wrong assay used. A symptom on TRT is a starting point; a lab value at trough on the right assay is the data that lets a prescriber act on it.
Three things go wrong without a defined schedule:
- Dose changes get made on bad data. A peak draw on once-weekly cypionate can read 1,400 ng/dL while the trough is 480 ng/dL. Cutting the dose based on the peak leaves the patient symptomatic at trough.
- Side effects get caught late. Hematocrit creep above 54 percent, PSA velocity above 1.4 ng/mL per year, and estradiol drift are all detectable months before they become problems — but only with scheduled draws.
- Rare adverse events get missed. Pulmonary embolism risk, atrial fibrillation signal, and acute kidney injury — all flagged in TRAVERSE (Lincoff AM et al., New England Journal of Medicine 2023) — depend on monitoring to detect early.
The schedule below is the clinical framework that the Endocrine Society, AUA, and large randomized trial protocols converge on. Specific intervals belong to your prescriber.
The schedule at a glance
Before walking through each visit, here is the full sequence — pre-TRT through annual maintenance — visualized as a timeline.
The pre-TRT baseline panel
Before testosterone is prescribed, both the Endocrine Society and the AUA require diagnostic confirmation of testosterone deficiency: at least two morning total testosterone measurements drawn on separate days, both below the lab's lower reference limit (commonly 264 ng/dL per Travison et al., JCEM 2017 harmonized reference). Morning draws matter because total testosterone follows a circadian rhythm with values up to 30 percent higher between 7-10 AM than late afternoon.
A complete pre-TRT panel typically extends well beyond total testosterone. The purpose is twofold: confirm the diagnosis, and establish a baseline for every marker that will be retested on therapy.
Markers commonly included on a pre-TRT panel
- Total testosterone — two morning draws on separate days; AM cortisol can be added to confirm the timing of the draw.
- Free testosterone — ideally by equilibrium dialysis (the gold standard) or calculated from SHBG and albumin. The direct analog free testosterone immunoassay is not recommended by the Endocrine Society.
- SHBG — sex hormone-binding globulin. High SHBG (often associated with hyperthyroidism, aging, or anticonvulsants) inflates total testosterone relative to free; low SHBG (often associated with insulin resistance, obesity, hypothyroidism) does the opposite.
- LH and FSH — distinguishes primary (testicular) from secondary (pituitary or hypothalamic) hypogonadism. Elevated LH and FSH point to primary; low or inappropriately normal point to secondary.
- Sensitive estradiol (LC-MS/MS) — baseline E2 to compare against post-TRT values.
- Prolactin — elevated prolactin can suppress LH and cause secondary hypogonadism. Substantial elevation (above ~25 ng/mL in men) warrants pituitary MRI to rule out prolactinoma.
- Complete blood count (CBC) — baseline hematocrit and hemoglobin before TRT-induced erythrocytosis is a possibility.
- Comprehensive metabolic panel (CMP) — kidney and liver function as a safety baseline.
- Lipid panel — total cholesterol, LDL, HDL, triglycerides; TRT can modestly lower HDL.
- Hemoglobin A1C — insulin resistance and metabolic syndrome are common in low-T populations and influence aromatization.
- PSA — in men 40 and older or with prostate cancer risk factors, per the AUA guideline. Baseline establishes the trajectory used to detect velocity changes on therapy.
- TSH — thyroid dysfunction can mimic low-T symptoms; a one-time check rules in or out a thyroid contribution.
- Vitamin D 25-OH — commonly added because vitamin D deficiency overlaps with low-T symptoms.
- Iron studies and ferritin — sometimes added for fatigue evaluation.
Pro tip on baseline draws: Pull the pre-TRT panel on two separate mornings to get two morning total testosterone values, both fasted, both before 10 AM. The Endocrine Society's requirement for two confirmatory low values exists because total testosterone has meaningful day-to-day variation. A single low value from an afternoon draw is not a diagnosis. See our companion piece on at-home testosterone test kits for context on which labs accept self-pay panels.
The 6-week initial follow-up panel
For injectable testosterone cypionate or enanthate, the first follow-up draw is most commonly performed around 6 weeks after starting the protocol. This is not arbitrary. The half-life of testosterone cypionate is approximately 8 days; 5 to 6 half-lives are required to reach steady state, which puts the first stable draw at roughly 6 weeks. The 2018 Endocrine Society guideline reflects this timing.
For testosterone gel, steady-state serum levels are reached within roughly 14 days, so an earlier 2-4 week follow-up is often appropriate. For testosterone pellets, the typical pattern is a peak draw at 4-6 weeks (when serum levels are at their maximum) and a trough draw shortly before the next implant.
Markers commonly drawn at 6 weeks
- Total testosterone — at trough for injectables (the morning before the next dose).
- Free testosterone — by equilibrium dialysis or SHBG-calculated.
- SHBG — can shift on TRT; rechecking informs the free T calculation.
- Sensitive estradiol — E2 typically rises proportionally with testosterone; first opportunity to see if the patient is a high-aromatizer phenotype.
- Hematocrit and hemoglobin — early hematocrit creep is detectable here, especially with high-peak protocols.
- Symptom assessment — energy, libido, mood, sleep, erection quality, exercise capacity. These are the actual targets of therapy; the labs exist to make symptom changes interpretable.
At this draw, the prescriber is asking three questions. Is the dose hitting a target serum testosterone (commonly mid-to-upper reference range at trough, roughly 500-900 ng/dL on most assays — though target ranges vary)? Is estradiol tracking proportionally and tolerably? Are early symptoms responding? Major dose changes typically wait until at least one full 6-week cycle has been completed at any new dose so that pre-steady-state numbers do not drive the change.
The 3-month maintenance panel
The 3-month panel is the first comprehensive maintenance check. By this point most acute symptom shifts (energy, libido, sleep) have resolved or stabilized, body composition changes are starting, and any erythrocytosis trend is becoming visible. The Endocrine Society and AUA both recommend hematocrit at 3-6 months, and PSA at 3-12 months for men 40 and older.
Markers commonly drawn at 3 months
- Total and free testosterone (at trough for injectables)
- SHBG
- Sensitive estradiol
- Complete blood count (CBC) — particular focus on hematocrit
- PSA — for men 40 and older or with risk factors
- Lipid panel — TRT can modestly lower HDL; this is the first chance to see the change
- Comprehensive metabolic panel — generally rechecked annually unless concerns
- Symptom assessment with a structured tool such as the ADAM questionnaire or a side effect checklist
The 3-month draw is also a decision point about adjuncts. If hematocrit is approaching 52-54 percent, dose reduction or therapeutic phlebotomy enters the conversation — covered in depth in our hematocrit on TRT article. If estradiol is symptomatic and elevated despite frequency adjustments, the conversation about an aromatase inhibitor begins — covered in our anastrozole and TRT guide. Most adjunct decisions wait until this 3-month data is in hand, not the 6-week draw.
6-month and 12-month retests
The 6-month draw is essentially a repeat of the 3-month panel and confirms that the protocol holds steady on the same dose. This is also the typical first opportunity to evaluate body composition changes (DEXA or simpler measures), bone density baseline if not previously obtained, and a structured side effect review.
What changes between 6 and 12 months
- Hematocrit trajectory becomes clearer. Most TRT-related erythrocytosis develops within the first 12 months. A patient holding hematocrit at 50 percent at 12 months is unlikely to suddenly cross 54 percent in year two.
- PSA velocity becomes interpretable. A PSA velocity above 1.4 ng/mL per year — calculated across the baseline, 6-month, and 12-month draws — is the threshold the AUA flags for urology referral.
- Body composition gains plateau. Lean mass changes from TRT are most pronounced in the first 12 months; further gains after that are smaller and more dependent on training and nutrition.
- HDL stabilizes. Any HDL drop on TRT typically appears in the first 6 months and then plateaus.
At the 12-month mark, the full pre-TRT panel is generally repeated as the annual baseline. This includes everything from CBC and CMP through PSA, lipids, A1C, and TSH if warranted by the clinical context.
Annual labs once stable
Once a patient is stable — symptoms controlled, hematocrit below the threshold, PSA stable, estradiol tolerable, no protocol changes — the cadence drops to annual labs. This is the maintenance state most patients live in for years.
The annual maintenance panel
- Total and free testosterone (at trough)
- SHBG
- Sensitive estradiol
- Complete blood count (focus on hematocrit)
- Comprehensive metabolic panel
- Lipid panel
- Hemoglobin A1C
- PSA (men 40 and older)
- Prolactin (if previously elevated or symptomatic)
- TSH (if symptomatic)
- Vitamin D 25-OH (often added for general health monitoring)
Any new symptom — fatigue, mood change, low libido, joint pain, edema — triggers an out-of-cycle draw rather than waiting for the annual visit. The schedule is a floor, not a ceiling.
One scenario: A 52-year-old man stable on 100 mg cypionate twice weekly for 18 months reports new joint pain and a libido drop over 8 weeks. His annual labs are 4 months away. The right move is an out-of-cycle sensitive estradiol and total testosterone draw at trough — not waiting. Joint pain in a stable TRT patient is a classic low-E2 signal and frequently means the protocol drifted (often from body composition change shifting aromatization). His prescriber may find E2 has dropped to 12 pg/mL and reduce frequency or dose to bring it back into range.
Draw timing: trough vs peak by ester and delivery method
Draw timing is the single highest-leverage decision in TRT lab interpretation. The same patient on the same dose can produce wildly different total testosterone numbers depending on when the blood is pulled. Inconsistent timing across visits makes serial comparisons useless.
Recommended timing by delivery method
| Delivery method | Half-life / kinetics | When to draw | What it tells you |
|---|---|---|---|
| Testosterone cypionate (weekly or twice-weekly IM/SC) | ~8 days | Trough — morning of next scheduled dose, before injection | Floor of weekly serum range; the value used to titrate dose |
| Testosterone enanthate (weekly IM/SC) | ~7 days | Trough — morning of next dose | Same as cypionate |
| Testosterone propionate (every other day) | ~0.8 days | Mid-interval; less peak/trough variation | Average serum level |
| Testosterone undecanoate (10-week IM) | ~21 days | Trough at week 10, before next injection | Low end of the cycle; FDA labeling prescribes this timing |
| Testosterone gel (daily) | Steady state ~14 days | 2-8 hours after morning application | Mid-day serum level reflecting absorption |
| Testosterone pellets (3-6 month implant) | Variable, peaks 4-6 weeks | Peak (4-6 weeks) and trough (before re-implant) | Both ends of the implant cycle |
| Nasal testosterone (Natesto, 3x daily) | Very short; rapid peaks | Per FDA labeling and prescriber direction | Peak-to-trough variability is wide; label-driven timing |
The principle behind every row in the table is the same: pick a draw time that is reproducible visit-to-visit and that captures the value the prescriber will act on. For cypionate and enanthate, that is trough. For gel, it is mid-day after application. For pellets, it is both peak and trough.
Why peak draws cause unnecessary dose reductions
On once-weekly testosterone cypionate, the serum testosterone curve looks roughly like a wave: a peak around days 1-3 post-injection, a steady decline, and a trough at day 7. A draw on day 2 in a man stable on 120 mg weekly might read 1,300 ng/dL — well above the typical lab reference range — while his trough on day 7 is 580 ng/dL. The day-2 number triggers a dose reduction that he does not need; the day-7 number reflects what his prescriber should be titrating against.
Splitting injections to twice-weekly flattens the peak-to-trough variation and reduces this problem, which is one reason twice-weekly is the modal protocol in current TRT clinical practice. See our companion comparison on TRT gel vs injections for the kinetics differences across delivery routes.
Visualizing peak vs trough across delivery methods
The chart below conceptually compares once-weekly injections, twice-weekly injections, and daily gel. Same average serum level, very different draw-time variability.
Conceptual illustration based on published pharmacokinetic profiles for testosterone cypionate, enanthate, and topical gel — not patient data.
What each marker means and the red-flag thresholds
A schedule without context is just a calendar. Here is what each marker on a typical TRT panel measures, why it matters, and the thresholds that prescribers commonly treat as red flags. Thresholds vary by guideline body and by individual prescriber — the values here are widely cited reference points, not absolute targets.
Total testosterone (TT)
- What it measures: All testosterone in serum — bound to SHBG, bound to albumin, and free.
- Reference range: The Endocrine Society's harmonized lower limit is approximately 264 ng/dL based on Travison et al. (JCEM 2017); upper limits depend on assay. Most TRT prescribers target a trough mid-to-upper reference range, often 500-900 ng/dL.
- Red flags: Trough TT below 350 ng/dL on a stable protocol generally signals under-dosing; trough TT above 1,000-1,100 ng/dL on injectables signals supraphysiological exposure and a likely candidate for dose reduction.
Free testosterone (FT)
- What it measures: The fraction of testosterone not bound to SHBG or albumin — the biologically active fraction.
- How to measure: Equilibrium dialysis is the gold standard. Calculated free testosterone (Vermeulen equation, using TT, SHBG, and albumin) is acceptable. The direct analog free testosterone immunoassay is not recommended by the Endocrine Society.
- Why it matters: In men with high or low SHBG, total testosterone can mislead. A man with SHBG of 80 nmol/L might have a normal total testosterone but symptomatically low free testosterone.
SHBG (sex hormone-binding globulin)
- What it measures: The protein that binds and inactivates testosterone in serum.
- Causes of high SHBG: Hyperthyroidism, aging, anticonvulsants, severe caloric restriction, hepatic disease.
- Causes of low SHBG: Insulin resistance, obesity, hypothyroidism, growth hormone excess, Cushing's.
- Why it matters on TRT: Low SHBG on TRT is common and can drive higher free testosterone than the total testosterone number suggests. Some men with low SHBG do better on lower total doses split into more frequent injections.
Sensitive estradiol (E2 by LC-MS/MS)
- What it measures: The aromatized estrogen metabolite of testosterone, accurately quantified at male concentrations.
- Why the sensitive assay matters: The standard immunoassay was validated for premenopausal women and is unreliable in men (Stanczyk FZ et al., JCEM 2007). Using the wrong assay is the single most common reason men end up on aromatase inhibitors they did not need.
- Reference points: No officially established target. Observational data suggest most men feel well at sensitive E2 of 20-40 pg/mL, though the range varies. The Endocrine Society 2018 guideline does not specify a target. See our deep-dive on estradiol on TRT.
Hematocrit (HCT)
- What it measures: The percentage of red blood cells in whole blood.
- Red-flag threshold: Both Endocrine Society and AUA guidelines recommend intervention at hematocrit above 54 percent — typically dose reduction, frequency change, or therapeutic phlebotomy.
- Timing of the rise: Most TRT-related erythrocytosis appears in the first 6-12 months and is more common with high-peak protocols (once-weekly injections, pellets) than with flatter delivery (gel, twice-weekly injections).
- Full coverage: See our hematocrit on TRT article for phlebotomy thresholds, blood donation logistics, and what TRAVERSE showed.
PSA (prostate-specific antigen)
- What it measures: A serine protease secreted by prostate epithelial cells; rises with prostate volume, inflammation, or malignancy.
- AUA guideline thresholds: Baseline PSA in men 40 and older. Recheck at 3-12 months on TRT, then annually. Urology referral generally triggered by PSA above 4 ng/mL, PSA velocity above 1.4 ng/mL per year, or any abnormal digital rectal exam.
- TRAVERSE evidence: The TRAVERSE trial (Lincoff et al., NEJM 2023) found no statistically significant excess of high-grade prostate cancer in men on TRT versus placebo over a mean follow-up of 33 months — though it was not powered for prostate cancer as a primary endpoint.
Lipid panel
- What it measures: Total cholesterol, LDL, HDL, triglycerides, non-HDL cholesterol.
- What changes on TRT: Modest HDL reduction is the most consistently observed effect. LDL and triglycerides are typically less affected. The TRAVERSE trial showed no statistically significant difference in cardiovascular events between TRT and placebo.
- Frequency: Annually once stable; sooner if abnormal at baseline or if concomitant statin therapy is being titrated.
Hemoglobin A1C
- What it measures: Average blood glucose over approximately the prior 3 months.
- Why it matters on TRT: Insulin resistance and metabolic syndrome are common in low-T populations. TRT may modestly improve insulin sensitivity in some men, but it is not a diabetes treatment. A1C tracking helps separate TRT-driven body composition changes from metabolic improvements.
- Frequency: Baseline and annually; quarterly if A1C is in the prediabetic or diabetic range.
Prolactin
- What it measures: An anterior pituitary hormone that, when elevated, can suppress LH and cause secondary hypogonadism.
- Threshold of concern: Substantial elevation (commonly above ~25 ng/mL in men) warrants pituitary MRI to rule out prolactinoma. The Endocrine Society guideline recommends this workup for clearly elevated prolactin in a man with secondary hypogonadism.
- Frequency on TRT: Baseline; not routinely retested unless symptoms (galactorrhea, vision changes, severe headache) suggest a pituitary issue.
LH and FSH
- What they measure: Pituitary gonadotropins that drive testicular testosterone production (LH) and spermatogenesis (FSH).
- Why they matter pre-TRT: Distinguish primary (testicular) hypogonadism (high LH/FSH, low T) from secondary (pituitary or hypothalamic) hypogonadism (low or inappropriately normal LH/FSH, low T).
- On TRT: Both are suppressed by exogenous testosterone via negative feedback. Routine retesting on stable TRT adds little unless fertility is the question — see our HCG on TRT article for the fertility-on-therapy framework.
Comprehensive metabolic panel (CMP)
- What it measures: Kidney function (BUN, creatinine, eGFR), liver enzymes (ALT, AST), electrolytes, glucose.
- Why it matters: Safety baseline. Oral testosterone formulations (older 17-alpha alkylated agents, less commonly used) have hepatic concerns; injectable and transdermal forms generally do not affect liver enzymes.
- Frequency: Baseline and annually.
What the TRAVERSE trial changed about TRT monitoring
The TRAVERSE trial (Testosterone Replacement Therapy for Assessment of Long-term Vascular Events and Efficacy Response in Hypogonadal Men), published by Lincoff et al. in the New England Journal of Medicine in 2023, was the largest randomized, placebo-controlled cardiovascular safety trial of testosterone therapy ever conducted: 5,246 men aged 45-80 with hypogonadism and elevated cardiovascular risk, followed for a mean of 33 months.
The headline finding: testosterone therapy was non-inferior to placebo for the primary composite cardiovascular endpoint (death from cardiovascular causes, nonfatal myocardial infarction, or nonfatal stroke). For the most-debated safety question in TRT — does it cause heart attacks — the answer from the highest-quality randomized trial available is no.
What TRAVERSE flagged for monitoring
- Pulmonary embolism: Numerically higher in the TRT group, though not the primary endpoint. The FDA TRT label already includes a warning about venous thromboembolism. Patients with prior VTE or thrombophilia warrant added vigilance and often a hematology consult before TRT.
- Atrial fibrillation: Numerically higher in the TRT group. New palpitations or irregular pulse warrant ECG.
- Acute kidney injury: Numerically higher in the TRT group, though small. This is one reason annual CMP is reasonable.
TRAVERSE did not change the core monitoring schedule, but it sharpened what to watch for in the first year of therapy — particularly in men with cardiovascular comorbidities. Our full breakdown of the trial design and findings is in the TRAVERSE trial explained.
Common monitoring mistakes that cause bad decisions
The schedule is straightforward. The mistakes are predictable. Here are the patterns that drive most monitoring-related dose errors.
1. Drawing labs at peak instead of trough
On once-weekly cypionate, peak vs trough total testosterone can differ by 700 ng/dL or more. A peak draw routinely produces a number above the lab's reference range and triggers a dose cut that leaves the patient symptomatic at trough. The fix: always draw at trough on injectables, document the timing on the order, and keep timing consistent across visits.
2. Ordering the standard estradiol immunoassay instead of the sensitive assay
The standard immunoassay cross-reacts with other steroid metabolites at male E2 concentrations and gives unreliable, often falsely elevated results (Stanczyk FZ et al., JCEM2007). The fix: explicitly order "Estradiol, Sensitive" (Quest) or "Estradiol, Ultrasensitive" (LabCorp) — also referenced as estradiol by LC-MS/MS.
3. Skipping SHBG when interpreting total testosterone
Two men with identical total testosterone of 600 ng/dL can have very different free testosterone if their SHBG differs (e.g., 25 vs 65 nmol/L). The fix: include SHBG on every panel, calculate free testosterone, and treat the calculated free T as the more clinically meaningful number for symptom correlation.
4. Missing the first-year hematocrit window
Most TRT-related erythrocytosis develops within 6-12 months of starting therapy. Skipping the 3-month or 6-month CBC means catching hematocrit at 56 percent at the annual visit instead of at 51 percent and intervening with a frequency change before phlebotomy is needed. The fix: do not skip the CBC at 3 and 6 months, especially on once-weekly or pellet protocols.
5. Using the wrong free testosterone method
The direct analog free testosterone immunoassay is not recommended by the Endocrine Society — it is unreliable. The fix: order calculated free testosterone (which requires SHBG and albumin) or equilibrium dialysis free testosterone.
6. Reacting to a single out-of-range value
Lab values have biological variability. A single elevated estradiol, a single hematocrit at 53 percent, or a single PSA bump is not a diagnosis. The fix: confirm any actionable lab finding with a repeat draw before changing dose or adding a medication. The exception is a markedly abnormal value (e.g., hematocrit above 56 percent, PSA above 4 ng/mL) that warrants immediate prescriber contact.
7. Not retesting after a protocol change
Any dose change, frequency change, ester change, or addition of HCG or anastrozole resets the steady-state clock. The fix: a 6-week post-change draw before evaluating whether the change worked.
Bone health note for any patient on chronic adjuncts: Long-term aromatase inhibitor use in men is associated with reduced bone mineral density. If a patient has been on anastrozole or another AI for more than 12 months, a baseline DEXA scan is reasonable to discuss with the prescriber, particularly in men over 50 or with other osteoporosis risk factors.
The bottom line
A TRT blood work schedule is not a wellness checklist. It is the clinical scaffolding that lets a prescriber catch erythrocytosis before it becomes phlebotomy, distinguish supraphysiological dosing from genuine optimization, separate symptomatic high E2 from a bad assay, and detect the rare adverse events TRAVERSE flagged.
Three rules keep most patients out of trouble. First, draw at trough on injectables and at consistent timing on every other delivery method. Second, always use the sensitive estradiol assay. Third, do not react to a single out-of-range value — confirm before changing.
For deeper context on individual markers, the next reads are estradiol on TRT and hematocrit on TRT. For broader monitoring framework, see the blood work pillar guide. For the cardiovascular safety question that anchors much of modern TRT monitoring, see the TRAVERSE trial explained. If you are weighing alternatives that change which markers matter most, compare enclomiphene vs TRT and clomid vs TRT.
Sources referenced in this article:
- Bhasin S et al., "Testosterone Therapy in Men With Hypogonadism: An Endocrine Society Clinical Practice Guideline," Journal of Clinical Endocrinology & Metabolism (2018).
- Mulhall JP et al., "Evaluation and Management of Testosterone Deficiency: AUA Guideline" (2018, updated 2024).
- Travison TG et al., "Harmonized Reference Ranges for Circulating Testosterone Levels in Men of Four Cohort Studies in the United States and Europe," Journal of Clinical Endocrinology & Metabolism (2017).
- Lincoff AM et al., "Cardiovascular Safety of Testosterone-Replacement Therapy" (TRAVERSE trial), New England Journal of Medicine (2023).
- Stanczyk FZ et al., "Limitations of direct estradiol and testosterone immunoassay kits," Journal of Clinical Endocrinology & Metabolism (2007).
- Vermeulen A, Verdonck L, Kaufman JM, "A critical evaluation of simple methods for the estimation of free testosterone in serum," Journal of Clinical Endocrinology & Metabolism (1999).
- Snyder PJ et al., "Effects of Testosterone Treatment in Older Men" (Testosterone Trials), New England Journal of Medicine (2016).
- Mayo Clinic Laboratories and Quest Diagnostics / LabCorp test catalogs — sensitive estradiol (LC-MS/MS) and equilibrium dialysis free testosterone assay specifications.
This article was written by the TRT FAQ Editorial Team and reviewed for alignment with current Endocrine Society and AUA guidance. It is updated periodically as new evidence emerges. Last content review: April 2026.
Frequently Asked Questions
What is the standard TRT blood work schedule?
Schedules vary by prescriber, but a widely used framework follows the 2018 Endocrine Society clinical practice guideline (Bhasin et al., JCEM) and the AUA testosterone deficiency guideline: a comprehensive baseline panel before starting TRT, a follow-up panel at roughly 6 weeks after initiation or any dose change, a 3-month panel, a 6-month panel, then annually once levels and symptoms are stable. Hematocrit and PSA carry their own monitoring cadence — typically baseline, 3-6 months, 12 months, then annually per AUA. Your prescriber decides the exact intervals.
Which labs should be drawn before starting TRT?
A complete pre-TRT panel typically includes total testosterone (two morning draws on separate days per Endocrine Society and AUA), free testosterone (ideally by equilibrium dialysis or calculated from SHBG and albumin), SHBG, LH and FSH, sensitive estradiol (LC-MS/MS), prolactin, complete blood count with hematocrit, comprehensive metabolic panel, lipid panel, hemoglobin A1C, PSA in men 40 and older or with risk factors, and TSH to rule out thyroid contribution. The exact panel is prescriber-determined.
When should I draw labs after starting TRT?
The first follow-up draw is most commonly performed around 6 weeks after starting injectable testosterone, which is roughly 5 to 6 half-lives for cypionate or enanthate and is the point at which steady-state serum levels are reached. This timing is reflected in the 2018 Endocrine Society guideline. For testosterone gel, steady state is reached faster (about 14 days), so an earlier follow-up is often appropriate. Pellets are typically rechecked at the 4-6 week peak and again at the trough before the next implant.
Should TRT blood work be drawn at trough or peak?
For weekly or twice-weekly testosterone cypionate or enanthate, most clinicians draw at trough — the morning of the next scheduled injection, before the dose. Trough draws give a reproducible floor and the value most relevant to dose titration. For testosterone gel, mid-morning 2-8 hours after application is typical. For testosterone pellets, both a peak (4-6 weeks) and a pre-implant trough are common. Consistency of timing across draws matters more than the absolute timing because it makes comparisons valid.
How often should hematocrit be checked on TRT?
The 2018 Endocrine Society guideline recommends checking hematocrit at baseline, 3-6 months, 12 months, then annually if stable, with intervention considered at hematocrit above 54 percent. The AUA guideline echoes the 54 percent threshold. Hematocrit rises are most common in the first 6-12 months on therapy and with high-dose, high-peak protocols. See our companion article on hematocrit on TRT for the full picture on phlebotomy and dose adjustment.
How often should PSA be checked on TRT?
The 2018 AUA testosterone deficiency guideline recommends a baseline PSA in men 40 and older or those with risk factors, a recheck at 3-12 months after starting TRT, then annually thereafter — alongside digital rectal exam timing per shared decision-making. PSA rises of more than 1.4 ng/mL in 12 months, or any PSA above 4 ng/mL, generally trigger urology referral. The TRAVERSE trial (Lincoff et al., NEJM 2023) found no statistically significant excess of high-grade prostate cancer in men on TRT versus placebo, though the trial was not powered for prostate cancer as a primary endpoint.
What estradiol test should men on TRT order?
The sensitive estradiol assay (LC-MS/MS) — labeled Estradiol Sensitive at Quest Diagnostics or Estradiol Ultrasensitive at LabCorp — is the appropriate test for men. The standard immunoassay was validated for premenopausal women and gives unreliable, often falsely elevated results at male E2 concentrations (Stanczyk et al., JCEM 2007). Ordering the wrong test is the single most common reason men end up on aromatase inhibitors they did not need.