Evidence explainerMen's Hormones & TRT

TRT Blood Tests: What Gets Checked Before and During Testosterone Therapy, and When

Before testosterone therapy: two morning testosterone tests, LH, hematocrit and, over 40, PSA. After: a testosterone level once the dose settles, hematocrit within the first months, then repeat tests every 6 to 12 months. Here is the schedule the two main US guidelines describe, and when to draw blood on each form.

By Kymata Labs EditorialPublished October 11, 2026Last verified October 11, 2026

Medical review pending. Written by our editorial team from the studies and documents cited below; a credentialed clinician has not reviewed it yet. Educational only, not medical advice.

Key takeaways

  • Before treatment the AUA asks for two early-morning total testosterone tests on separate days, LH, hemoglobin and hematocrit (below 50% before starting) and, in men over 40, a PSA [1].
  • The AUA aims for a testosterone level in the middle of the normal range, 450 to 600 ng/dL for most labs, together with symptom improvement [1].
  • First follow-up depends on the form: 2 to 4 weeks for gels, after three to four injection cycles for cypionate or enanthate, drawn mid-cycle by convention [1]; the Endocrine Society says 3 to 6 months, midway between injections [2].
  • Once stable, the AUA repeats testosterone and hematocrit every 6 to 12 months, keeping hematocrit below 54% [1]; the Endocrine Society checks hematocrit at baseline, 3 to 6 months, then yearly [2].
  • If testosterone normalizes but symptoms don't improve after 3 to 6 months, the AUA says stopping should be discussed [1].

Before the first prescription

The diagnosis itself rests on symptoms plus two low early-morning tests; our low testosterone symptoms guide covers that step. Once low testosterone is confirmed, the AUA's baseline list is short [1]:

  • Total testosterone: two early-morning measurements on separate occasions, at the same lab with the same assay [1].
  • LH (luteinizing hormone), to help tell whether the problem starts in the testes or the pituitary; prolactin if LH is low or low-normal [1].
  • Hemoglobin and hematocrit, to confirm a starting hematocrit below 50% [1].
  • PSA in men over 40, and in any man with a history of prostate cancer [1]. The Endocrine Society frames prostate monitoring as a shared decision for men 55 to 69, and for men 40 to 69 at higher risk [2].
  • Estradiol if there is breast tenderness or enlargement; FSH optionally for men interested in fertility [1].

When to draw blood on each form

Testosterone levels swing differently with each product, so timing changes what a result means.

  • Injections (cypionate or enanthate): AUA says test after at least three to four cycles, historically mid-cycle [1]. The Endocrine Society says measure midway between injections, and adjust the dose or interval if the mid-interval level is above 600 or below 350 ng/dL [2].
  • Gels: AUA says 2 to 4 weeks after starting [1]; the Endocrine Society says 2 to 8 hours after applying, once on treatment for at least a week [2]. The AUA asks men on daily products to use their medication on the day of the blood draw [1].
  • Patches: 3 to 12 hours after application [2].
  • Pellets: AUA tests 2 to 4 weeks after insertion, then at 10 to 12 weeks [1]; the Endocrine Society measures at the end of the dosing interval [2].
  • Oral testosterone undecanoate: 3 to 5 hours after taking it with a meal containing fat [2].
  • Clomiphene, hCG or anastrozole: no sooner than four weeks after starting [1].

The ongoing schedule

After the first follow-up, the guidelines and labels describe this rhythm. Where they differ, both are shown.

  • Testosterone: every 6 to 12 months once stable [1].
  • Hematocrit: AUA every 6 to 12 months, or sooner depending on earlier results, to keep it below 54% [1]; Endocrine Society and labels at 3 to 6 months after starting and then yearly [2][3].
  • PSA: Endocrine Society checks PSA and a prostate exam 3 to 12 months after starting for men who chose monitoring, then follows routine screening guidance [2]; AUA uses shared decision-making in line with its prostate cancer screening guideline [1].
  • Estradiol: in men who develop breast symptoms and in all men on aromatase inhibitors; optional on SERMs [1].
  • LH: four weeks after starting a SERM if testosterone stays low, and if a SERM stops working [1].
  • Lipids and liver tests: labels advise periodic checks of serum testosterone, PSA, hemoglobin, hematocrit, liver tests and lipids [3].
  • Bone density: after 1 to 2 years in men with osteoporosis [2].

When a PSA result prompts a urology referral

The Endocrine Society recommends a urology consultation if any of these occur on testosterone [2]:

  • PSA rises by more than 1.4 ng/mL within 12 months of starting [2].
  • A confirmed PSA above 4 ng/mL at any time [2].
  • A prostate abnormality on digital rectal exam, or substantially worse urinary symptoms [2].

Labs are only half the review

The Endocrine Society evaluates men 3 to 12 months after starting, then yearly, for whether symptoms have responded and for side effects [2]. The AUA does not recommend symptom questionnaires to decide who gets testosterone or to track response [1], and says that if testosterone normalizes without symptom improvement after three to six months, stopping should be discussed [1].

Labels also call for periodic blood-pressure checks [3]. TRAVERSE showed PSA rises more on testosterone than placebo in the first year, so a first-year rise is expected and the thresholds above decide what needs follow-up [4].

Getting tests done

Online TRT clinics differ in which labs they include and how often they repeat them; our online TRT comparison marks labs as included only when the clinic's own page says so. You can also order your own blood work and bring results to your prescriber.

Ask any clinic which baseline labs it orders, when it checks hematocrit and PSA, and what it does if hematocrit reaches 54%.

This guide explains what guidelines and studies say. It is not medical advice: a licensed clinician decides whether testosterone or any alternative is right for you, and at what dose.

Partners we link to

  • Mito HealthPaid linkOrder your own blood work without a doctor's visit. Its total testosterone test at Quest was $4.32 for members ($9/mo membership) or $6.05 without, on Oct 11, 2026; any lab order or draw fee is itemized before you pay.See Mito Health's lab prices (opens in new tab)

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Quick answers

What labs are needed before starting TRT?

The AUA lists two early-morning total testosterone tests, LH, hemoglobin and hematocrit, and a PSA for men over 40, plus prolactin if LH is low and estradiol if there are breast symptoms [1].

When should blood be drawn on testosterone injections?

After at least three to four injection cycles, mid-cycle by convention (AUA) [1]. The Endocrine Society says midway between injections, 3 to 6 months after starting [2].

How often are blood tests needed on TRT?

Once stable, the AUA repeats testosterone and hematocrit every 6 to 12 months [1]; the Endocrine Society checks hematocrit at 3 to 6 months and then yearly [2].

What testosterone level is the target on TRT?

The AUA aims for the middle tertile of the normal range, 450 to 600 ng/dL for most labs, with symptom improvement [1]; the Endocrine Society aims for the mid-normal range [2].

What PSA change is a concern on TRT?

The Endocrine Society advises urology referral for a rise of more than 1.4 ng/mL within 12 months, a confirmed PSA above 4 ng/mL, an abnormal prostate exam or substantially worse urinary symptoms [2].

More in Men's Hormones & TRT

References

  1. [1]Evaluation and Management of Testosterone Deficiency (2024). American Urological Association, 2024.
  2. [2]Testosterone Therapy in Men With Hypogonadism: An Endocrine Society Clinical Practice Guideline. J Clin Endocrinol Metab, 2018. PMID 29562364
  3. [3]AndroGel (testosterone gel) 1.62% prescribing information. DailyMed, U.S. National Library of Medicine, 2025.
  4. [4]Prostate Risk and Monitoring During Testosterone Replacement Therapy. J Clin Endocrinol Metab, 2024. PMID 38753865

Dietary supplements are not intended to diagnose, treat, cure or prevent any disease, and these statements have not been evaluated by the FDA. Prescription options need a licensed clinician. Talk to your clinician or pharmacist before starting anything new, especially if you take prescription medicines, are pregnant or breastfeeding.

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