May 18, 2026

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TRT & Hormones

TRT Bloodwork: The 12 Labs That Matter, Target Ranges and When to Test

TRT bloodwork and hormone lab monitoring explained

TRT & HORMONES · BLOODWORK

TRT BLOODWORK: THE 12 LABS THAT MATTER, TARGET RANGES AND WHEN TO TEST

TRT bloodwork is the set of blood tests used before and during testosterone therapy. It confirms the diagnosis, shows the dose is working, and catches side effects that appear in blood long before you feel them. Testosterone is only one of them.

This guide lists the 12 TRT labs, the target ranges, the numbers that change the plan, and when to test. Figures come from PubMed abstracts, the Endocrine Society guideline and the testosterone gel label, listed at the end. Start with what is TRT if you are new to the series.

Mark Reynolds

Bloodwork and Health Editor · Updated October 2026

TRT bloodwork in three numbers

Three numbers drive most TRT bloodwork decisions: the testosterone target on therapy, the hematocrit line, and how often the blood count should be repeated.

350to 750 ng/dL

Testosterone target on the gel label and in TRAVERSE

The gel label adjusts the dose to keep pre-dose morning testosterone between 350 and 750 ng/dL (AndroGel label). TRAVERSE used the same window (PMID 37326322).

54%hematocrit line

Where guidelines call it erythrocytosis

The Endocrine Society defines erythrocytosis as hematocrit above 54 percent (Endocrine Society guideline, PMID 29562364). Canadian guidance says stop or reduce the dose above it (PMID 28150363).

3.69xodds vs placebo

Hematocrit over 50% on testosterone

In 19 trials, men on testosterone were nearly four times as likely to reach hematocrit above 50 percent (PMID 16339333).

Every figure here comes from a PubMed abstract, the Endocrine Society guideline text or the AndroGel 1.62% label, all listed at the end. Lines marked rule of thumb are common practice, not study results. MuscleScience does not interpret individual lab results.

What this TRT bloodwork guide covers

Covered

The 12 TRT labs: what each TRT blood test answers and which ones are required.

Target ranges and timing: where testosterone should sit and when to draw it.

Red flags: the results that change the plan, and the monitoring schedule by visit.

Not covered

Reading your own results. That belongs to the clinician who ordered them.

Labs on a steroid cycle. See blood tests before steroids.

The 12 TRT blood tests and what each one answers

In TRT bloodwork, a baseline is not optional. Once testosterone starts, LH and FSH are suppressed and hematocrit rises. Anything not measured before the first dose can never be separated from the drug.

The 12 TRT labs: what each answers and the numbers to know.
Test	What it answers	Numbers to know
Total testosterone	Is the diagnosis real, and is the dose landing in range?	Diagnosis: under 264 to 300 ng/dL on 2 fasting draws between 7 and 10 am (PMID 42207626). On therapy: 350 to 750 ng/dL pre-dose (AndroGel label).
Free testosterone	How much is available when SHBG is off.	Use dialysis or a formula (PMID 29562364). Direct analog assays are not reliable (PMID 10523012).
SHBG	Why total and free testosterone disagree.	Obesity and diabetes lower SHBG, so calculated free T is needed (PMID 42207626).
LH and FSH	Testes problem or brain signal problem?	Measure at diagnosis to split primary from secondary (PMID 42207626). TRT suppresses both.
Prolactin	A pituitary cause?	Check in secondary hypogonadism. MRI if testosterone is under 150 ng/dL or prolactin stays high (Endocrine Society guideline, PMID 29562364).
Estradiol	Context for breast or sexual symptoms.	Use a sensitive LC-MS/MS test; immunoassay misreads male levels (PMID 22423144).
Hemoglobin and hematocrit	Is red cell production running too high?	Before, at 3 to 6 months, then yearly; stop if elevated (AndroGel label).
PSA	Prostate baseline and change.	Monitor on therapy (AndroGel label). Refer if it rises over 1.4 ng/mL or tops 4.0 in year one (Endocrine Society guideline, PMID 29562364).
Lipid panel	Heart risk context.	Monitor periodically (AndroGel label). HDL fell as the dose rose (PMID 11701431).
Liver enzymes	Liver context.	Weightlifting alone raised AST and ALT for at least 7 days (PMID 17764474).
Kidney markers	Kidney context.	TRAVERSE saw more acute kidney injury on testosterone (PMID 37326322). Rule of thumb: creatinine runs higher in muscular men.
Glucose and HbA1c	Metabolic context.	Obesity lowers testosterone; weight loss of at least 5 percent raises it (PMID 42207626).

Blood pressure belongs on the same sheet. The gel label says to check it periodically, and not to use the gel with uncontrolled hypertension (AndroGel label). More in blood pressure on TRT.

For single markers, see total vs free testosterone, SHBG explained, CBC markers and the lipid panel.

TRT bloodwork: young classic physique athlete pressing a cotton pad on his arm after a blood draw, with capped sample tubes in a rack beside him — Baseline TRT labs must be drawn before the first dose. After that, the drug changes the numbers.

YouWhat this means for you. Get the full baseline before your first dose. Without it, no later TRT blood test can tell you what the drug changed.

TRT bloodwork targets: where testosterone should sit

The Endocrine Society aims for mid-normal testosterone on therapy (PMID 29562364). The healthy range for men aged 19 to 39 is 264 to 916 ng/dL (PMID 28324103).

For TRT bloodwork, the gel label puts numbers on that. It keeps the dose if pre-dose morning testosterone is 350 to 750 ng/dL, lowers it above 750, and raises it below 350 (AndroGel label).

TRAVERSE, the largest safety trial, used the same 350 to 750 ng/dL window in 5,246 men (PMID 37326322). Its safety results apply to men kept in that range.

750ng/dL: the top of the testosterone window on the gel label and in TRAVERSE. Above it, the label lowers the dose (AndroGel label).

Higher is not better. In a dose study, HDL fell as testosterone rose (PMID 11701431), and hematocrit climbed with every dose step (PMID 18160461).

YouWhat this means for you. On TRT labs, a result in the middle of the range is the goal. A high-normal or above-range number is a reason to review the dose, not a badge.

When to get TRT bloodwork

For diagnosis, testosterone needs 2 fasting samples between 7 and 10 am on separate days (PMID 42207626). The gel label also asks for two morning measurements on separate days (AndroGel label).

On the gel, the label checks pre-dose morning testosterone at about 14 and 28 days, and after any dose change (AndroGel label). After that, it is assessed periodically.

Timing TRT blood tests by form.
Form	When to draw	Source
Gel 1.62%	Morning, before the daily dose, at about 14 and 28 days	AndroGel label
Weekly injection	Same day of the cycle and same hour every time	Rule of thumb
Any form, after a change	Repeat testosterone after a dose change	AndroGel label
Diagnosis, any form	2 fasting draws between 7 and 10 am	PMID 42207626

For injections there is no label rule here. The rule of thumb is consistency: same point in the cycle, same time, fasting, same lab. More on peaks and troughs in TRT injection frequency.

YouWhat this means for you. Write down the day and hour of each draw. A TRT blood test that cannot be compared with the last one is wasted money.

4 TRT bloodwork results that change the plan

Most TRT bloodwork is read as trends. Four results have clear action points.

1. Hematocrit too high. It is the most frequent side effect of testosterone in trials (PMID 16339333). The rise is dose dependent and bigger in older men (PMID 18160461).

Short acting injections carry the highest risk (PMID 28526632). The gel label says to stop until hematocrit falls to an acceptable level (AndroGel label). Canadian guidance uses 54 percent as the line (PMID 28150363).

Blood donation alone did not keep hematocrit under 54 percent in men on TRT. 44 percent of repeat donors stayed high (PMID 28150363). Details in high hematocrit on TRT.

2. PSA rising fast. In year one, the Endocrine Society refers men to urology for a confirmed PSA rise over 1.4 ng/mL above baseline (Endocrine Society guideline, PMID 29562364). The same applies to a PSA over 4.0.

Testosterone did not increase prostate cancer in 22 trials with 2,351 men, but short term use did raise PSA (PMID 24445948).

3. Testosterone above range. Above 750 ng/dL pre-dose, the gel label lowers the dose (AndroGel label). A high level also drives hematocrit up (PMID 18160461).

4. Good labs, no better symptoms. The Endocrine Society bases continuing therapy on symptom response and side effects (PMID 29562364). If a normal level changes nothing, the symptoms may have another cause.

YouWhat this means for you. In TRT bloodwork, hematocrit and PSA are the two labs with real action points. Never skip the blood count because you feel fine.

Estradiol on TRT labs: test it properly, then mostly leave it alone

Estradiol rises with testosterone; in 547 men the two climbed together (PMID 37261881). That is expected. In healthy men, blocking estrogen raised body fat and cut sexual function (PMID 24024838).

The Endocrine Society monitoring plan lists testosterone, hematocrit and prostate risk, not routine estradiol (PMID 29562364).

When estradiol is part of TRT bloodwork, the method matters. A standard immunoassay agreed poorly with mass spectrometry at male levels, correlation only 0.32 (PMID 22423144).

YouWhat this means for you. Ask for a sensitive LC-MS/MS estradiol and read it with the testosterone from the same draw. More in estradiol on TRT and the E2 to T ratio calculator.

LH, FSH and sperm: the labs TRT switches off

TRT bloodwork must include fertility if it matters to you. Outside testosterone shuts down the brain signal. In a fertility clinic, 88.4 percent of men taking testosterone had no sperm in their sample (PMID 24094422).

By 6 months after stopping, 65 percent of men without another cause had recovered. That means about a third had not (PMID 24094422).

88.4%Men taking testosterone who had no sperm in their semen sample at a fertility clinic (PMID 24094422).

In a pooled analysis of 1,549 men, sperm took a median 3.4 months to recover to 20 million per mL after stopping (PMID 16650651).

The Endocrine Society advises against starting TRT in men planning fertility in the near term (PMID 29562364). LH and FSH only mean something at baseline; on therapy they are simply suppressed.

YouWhat this means for you. If children are in your plans at all, get a semen analysis before the first dose. Read TRT and fertility first.

TRT bloodwork schedule by visit: when each TRT blood test is due

This TRT labs plan combines the guideline monitoring plan (PMID 29562364) with the gel label (AndroGel label). Clinics may add tests or shorten gaps.

TRT bloodwork schedule by visit.
Visit	TRT labs	Source
Before starting	2 morning fasting testosterone tests, LH, FSH, SHBG, CBC, PSA, lipids, glucose, blood pressure; prolactin if LH is low; semen analysis if fertility matters	PMID 42207626; AndroGel label; PMID 29562364
About 2 to 4 weeks (gel)	Pre-dose testosterone at about 14 and 28 days	AndroGel label
3 to 6 months	Hematocrit	AndroGel label
3 to 12 months	Prostate risk check, symptoms, side effects	PMID 29562364
After a dose change	Testosterone, CBC	AndroGel label; rule of thumb for CBC
Yearly	Hematocrit, testosterone, lipids, blood pressure; PSA per screening after year one	AndroGel label; Endocrine Society guideline

TRAVERSE found no rise in major heart events, but more atrial fibrillation, acute kidney injury and lung clots (PMID 37326322). Blood pressure and kidney markers cover that ground. See kidney markers.

TRT bloodwork review: young physique athlete in a black polo across a desk from a doctor who holds printed lab results — A TRT blood test schedule only works if each result is compared with the baseline and the last visit.

YouWhat this means for you. Put the next TRT blood test date in your calendar when you leave each visit. The schedule only protects you if it actually happens.

5 mistakes that make TRT bloodwork unreadable

1. One draw at a random time. Diagnosis needs 2 morning fasting draws (PMID 42207626). Monitoring needs a fixed point in the cycle.

2. The wrong free testosterone test. Direct analog assays are not reliable (PMID 10523012). Use dialysis or a calculated value from total T and SHBG.

3. Immunoassay estradiol, then a blocker. The standard test misreads male estradiol (PMID 22423144). Test it properly before anyone acts.

4. Skipping the CBC. High hematocrit is the most frequent side effect and causes no symptoms early (PMID 16339333).

5. Reading liver enzymes after a heavy session. Weightlifting raised AST and ALT for at least 7 days in healthy men (PMID 17764474). Rule of thumb: skip hard training for a few days before labs.

YouWhat this means for you. Most bad TRT lab decisions come from a bad sample, not a bad body. Control the timing, the method and the training before the draw.

TRT bloodwork: frequently asked questions

What blood tests are needed for TRT?

Before starting: 2 morning fasting testosterone tests, LH and FSH, a blood count, PSA, and usually SHBG, lipids and glucose (PMID 42207626, AndroGel label). Prolactin is added when LH is low (Endocrine Society guideline).

How often is TRT bloodwork done?

On the gel label, hematocrit is checked before starting, at 3 to 6 months, then yearly. Testosterone is checked at about 14 and 28 days (AndroGel label). Prostate risk is checked at 3 to 12 months (PMID 29562364).

What should testosterone be on TRT?

Mid-normal (PMID 29562364). The gel label keeps the dose when pre-dose testosterone is 350 to 750 ng/dL (AndroGel label), the same window used in TRAVERSE (PMID 37326322).

What hematocrit is too high on TRT?

The Endocrine Society calls hematocrit above 54 percent erythrocytosis (Endocrine Society guideline). Canadian guidance says stop or reduce the dose above it (PMID 28150363).

Does TRT raise PSA?

Short term use raised PSA, but 22 trials found no increase in prostate cancer (PMID 24445948). The Endocrine Society refers men if PSA rises over 1.4 ng/mL or tops 4.0 in year one (Endocrine Society guideline).

Should estradiol be tested on TRT?

It is not part of the routine Endocrine Society plan (PMID 29562364). If tested, use a sensitive LC-MS/MS method, since immunoassay misreads male levels (PMID 22423144).

Do I need to fast for TRT labs?

Yes for diagnosis: 2 fasting samples between 7 and 10 am (PMID 42207626). Keep the same conditions for follow up tests.

Does TRT affect sperm tests?

Yes. 88.4 percent of men on testosterone at a fertility clinic had no sperm, and about two thirds recovered within 6 months of stopping (PMID 24094422).

Sources and further reading

Every figure on this page comes from one of the 18 sources below. That is 17 papers checked against PubMed on 27 October 2026, plus the AndroGel 1.62% label on DailyMed. Lines marked rule of thumb are common practice, not study results. Reference links are dofollow to support open science.

Testosterone Therapy in Men With Hypogonadism: An Endocrine Society Clinical Practice Guideline

Verified

Bhasin S, et al. J Clin Endocrinol Metab. 2018;103(5):1715-1744. PMID 29562364. Thresholds for hematocrit, PSA referral and prolactin were checked against the full guideline text.