TRT Blood Work: Which Labs to Check, When, and What the Numbers Mean

By the JustLabs editorial teamLast reviewed October 24, 202619 sources

The short answer

TRT blood work starts with two fasting morning total testosterone tests, plus LH/FSH, hematocrit and, for many men over 40, PSA. Guidelines then recheck testosterone and hematocrit 3–6 months after starting, and again every year[1]. On weekly or biweekly injections, testosterone is drawn midway between doses. A hematocrit above 54% means therapy is paused[1].

Key takeaways

  • Before TRT: two early-morning, fasting total testosterone tests below about 300 ng/dL, with symptoms. Add LH/FSH to find the cause. Add free testosterone when SHBG may be off[2][3].
  • Schedule: testosterone and hematocrit at baseline and 3–6 months. Then hematocrit every year. PSA at 3–12 months for men 55–69, or 40–69 at higher risk[1].
  • Timing matters: on cypionate or enanthate, draw blood midway between injections. The goal is 350–600 ng/dL there. On gels, draw 2–8 hours after you apply[1].
  • Red flags: hematocrit above 54%. A PSA rise of more than 1.4 ng/mL in the first year. Or a confirmed PSA above 4 ng/mL. All lead to a pause or a urology referral[1].
  • Estradiol: the AUA advises it for men with breast symptoms. Neither guideline makes routine estradiol "management" part of standard monitoring[3][1].
  • Heart safety: in TRAVERSE, heart attacks, strokes and heart deaths were about the same on testosterone gel and placebo, 7.0% vs 7.3%[4].

What blood work do you need before starting TRT?

Both main guidelines agree on the first step. Prove that testosterone is truly low, more than once, and find out why. The Endocrine Society says to diagnose low testosterone only in men with symptoms and "unequivocally and consistently" low levels[2]. The American Urological Association (AUA) uses a total testosterone below 300 ng/dL on two early-morning draws as a reasonable cutoff. Symptoms alone are not enough. One low value is not enough either[3].

The table below lists the baseline labs. It shows what each one checks and when guidelines use it. You will also see the number that changes the plan. JustLabs prices for each test sit next to the rows.

TRT blood tests: what each checks, when, and the threshold that matters
TestWhat it checksWhen guidelines use itKey threshold or meaningJustLabs price
Total and free testosteroneWhether testosterone is low, then whether dosing reaches the targetTwo fasting morning draws before TRT; again at 3–6 months, then every 6–12 months[1][3]Below 300 ng/dL on two draws supports low T[3]. On injections, 350–600 ng/dL at mid-interval[1]$34
SHBGThe protein that binds testosterone; it changes how much is freeWhen total T is borderline or a condition shifts SHBG (obesity, diabetes, aging, liver disease, thyroid disease)[2][5]Abnormal SHBG means free testosterone gives the clearer picture[2]$18
LH and FSHPituitary signals to the testes; separate primary from secondary low TOnce, at diagnosis[5]High LH/FSH points to the testes; low or normal points to the pituitary or hypothalamus[5]$18
ProlactinA pituitary hormone that can suppress testosteroneWhen LH is low or low-normal[3][5]A high result leads to more pituitary testing$12
CBC (hematocrit)The share of blood made of red cellsBaseline, 3–6 months, then every year[1]Above 48% at baseline needs caution[5]. Above 54% on TRT means a pause[1]$6
PSAA prostate protein used for cancer risk checksBefore TRT and at 3–12 months for men 55–69, or 40–69 at higher risk[1]; AUA: baseline over age 40[3]Above 4 ng/mL (or above 3 at high risk) before TRT needs urology review first[2]$12
EstradiolThe main estrogen; men make it from testosteroneAUA: before TRT in men with breast symptoms or gynecomastia[3]No guideline target range on TRT; read with symptoms$15
Lipid panelCholesterol, including HDLLabels say "periodically"[6]HDL can fall at high doses[7]$8
CMP (liver and kidney)Liver enzymes, kidney function, glucoseLabels say liver tests "periodically"[6]A general safety baseline; your clinician sets the timing$9.50

Thresholds come from the Endocrine Society 2018 guideline and the AUA guideline. Labs are tools for your clinician to interpret. They are not a diagnosis on their own. Live catalog prices. Every order adds one $18 Lab & Physician Order Fee, however many tests it includes.

Why two fasting morning testosterone tests?

Testosterone swings during the day and from one day to the next. Food and sugar push it down. So the Endocrine Society says to measure it in the morning after an overnight fast. It also says to repeat the test to confirm a low result[5][2]. Do not test while you are sick or still recovering from an illness. A short illness can lower the number for a while[5].

Drug labels set the same rule. The AndroGel label says to confirm low testosterone "in the morning on at least two separate days" before starting[6]. Our fasting guide and blood test preparation hub cover what to skip the night before. If you are early in the process, the low testosterone lab guide explains the full workup.

When does free testosterone or SHBG matter?

Most testosterone in blood is bound to SHBG. Only a small share is free. When SHBG is high or low, total testosterone can mislead. The Endocrine Society advises free testosterone when total T is near the low end of normal. It also advises it when you have a condition that changes SHBG[2]. Obesity, diabetes and an underactive thyroid lower SHBG. Aging, liver disease, an overactive thyroid, HIV and estrogen use raise it[5].

The JustLabs free and total testosterone test reports both numbers from one draw. SHBG is a separate test. See the normal ranges page for how a result is read.

Why check LH, FSH and prolactin before TRT?

Low testosterone has two main sources. Either the testes are not making enough (primary). Or the pituitary is not sending the signal (secondary). The Endocrine Society tells these apart with LH and FSH[5]. When the pattern points to the pituitary, it adds prolactin and iron saturation[5]. The AUA likewise orders prolactin when LH is low or low-normal[3].

Do this before the first dose. Once you start TRT, LH and FSH drop. The pattern you need to find the cause is then gone[8]. The JustLabs FSH and LH test and prolactin test cover this step.

Which safety labs come before the first dose?

The Endocrine Society advises against starting TRT in some cases without more workup. These include a PSA above 4 ng/mL, or above 3 ng/mL in men at higher risk. Higher risk includes Black men and men with a father or brother who had prostate cancer. Elevated hematocrit and plans to father a child soon are also on the list[2]. The guideline's risk table flags a baseline hematocrit above 48% (above 50% for men living at high altitude)[5].

So a baseline CBC is standard. So is a PSA for most men over 40[3]. Labels also ask for liver and lipid checks over time. A CMP and lipid panel give you a starting point to compare against[6].

How often do you need blood work on TRT?

The Endocrine Society sets a simple rhythm. See the patient 3–12 months after starting, then once a year. Check testosterone at 3–6 months. Check hematocrit at baseline, at 3–6 months and then every year[1]. The AUA puts testosterone checks every 6–12 months while on therapy. It also suggests stopping if symptoms have not improved by 3–6 months[3]. Gel labels match this. They check hematocrit before treatment, at 3–6 months and then yearly[6].

TRT monitoring schedule: which labs, when

Testosterone and hematocrit are checked at baseline, at 3–6 months and yearly. PSA depends on age and risk. Estradiol, SHBG and LH/FSH apply only in some cases.

  • Guideline-recommended for men on TRT
  • Only in some men (age, risk, symptoms or borderline results)
TRT monitoring schedule: which labs, when
TestBefore starting3–6 months12 monthsEvery year
Total testosteroneGuideline-recommended for men on TRTGuideline-recommended for men on TRTGuideline-recommended for men on TRTGuideline-recommended for men on TRT
Hematocrit (CBC)Guideline-recommended for men on TRTGuideline-recommended for men on TRTGuideline-recommended for men on TRTGuideline-recommended for men on TRT
PSAOnly in some men (age, risk, symptoms or borderline results)Only in some men (age, risk, symptoms or borderline results)Only in some men (age, risk, symptoms or borderline results)Only in some men (age, risk, symptoms or borderline results)
EstradiolOnly in some men (age, risk, symptoms or borderline results)NoNoNo
LipidsOnly in some men (age, risk, symptoms or borderline results)NoNoOnly in some men (age, risk, symptoms or borderline results)
LH/FSHGuideline-recommended for men on TRTNoNoNo
ProlactinOnly in some men (age, risk, symptoms or borderline results)NoNoNo
SHBGOnly in some men (age, risk, symptoms or borderline results)NoNoNo
Source: [1], [3], [5], [6]

The chart marks only what a guideline or FDA label supports. "If" cells apply to some men only. Examples are PSA by age and risk, estradiol for breast symptoms, and SHBG when total T is borderline. A dose change usually restarts the clock. Many prescribers recheck testosterone and hematocrit a few months after any change.

What happens at the 3–6 month check?

This visit answers three questions. Is testosterone in range at the right point in the dose cycle? Has hematocrit climbed too far? For men in the PSA age groups, has PSA moved? The Endocrine Society aims for the mid-normal range. On injections, a mid-interval result above 600 or below 350 ng/dL prompts a dose or schedule change[1]. PSA and a prostate exam are due 3–12 months after starting in men 55–69, or 40–69 at higher risk[1].

Gels can need an earlier check. The AndroGel 1.62% label adjusts the dose based on a morning, pre-dose level at about 14 and 28 days[6]. Ask your prescriber which schedule fits your product.

What gets checked every year on TRT?

After the first year, the plan settles. Hematocrit is checked every year[1]. Testosterone is checked every 6–12 months[3]. After year one, prostate checks follow standard screening rules for your age and race[1]. Labels also ask for periodic PSA, liver and lipid tests. They ask for blood pressure checks too[6][8].

Many men fold these labs into a yearly physical. Our annual blood work guide shows how the core panel overlaps with TRT monitoring. That way you don't order the same test twice.

When should you get blood drawn on TRT? Trough, peak or midway

Timing is the most common reason a TRT result looks wrong. Testosterone rises after a dose and falls before the next one. A draw on the wrong day can make a good dose look too high or too low. The Endocrine Society gives each product its own draw time[1].

When to draw testosterone, by TRT formulation
FormulationWhen to draw testosteroneSource
Testosterone cypionate or enanthate injectionsMidway between injections; adjust if above 600 or below 350 ng/dLEndocrine Society[1]
Testosterone gels2–8 hours after applying the gelEndocrine Society[1]
AndroGel 1.62% (dose titration)Morning, before the day's dose, at about 14 and 28 daysFDA label[6]
Patches3–12 hours after applyingEndocrine Society[1]
PelletsAt the end of the dosing intervalEndocrine Society[1]
Long-acting testosterone undecanoate injectionAt the end of the interval, just before the next shotEndocrine Society[1]
Oral testosterone undecanoate3–5 hours after taking it with a fat-containing mealEndocrine Society[1]

Your prescriber may use a different time point, such as a trough, for a specific reason. Note the date and time of your last dose so the result can be read correctly.

Weekly and biweekly shots are where most confusion happens. Midway on a weekly schedule means about day 3 or 4 after the shot. On an every-2-weeks schedule, it means about day 7. Some prescribers prefer a trough, drawn just before the next dose, to confirm levels do not dip too low. That is a valid choice. Just compare trough to trough over time, not trough to peak.

Draw-day tips that keep results comparable

Use the same time of day and the same point in your dose cycle each time. Drink water as usual, since dehydration can concentrate blood. See water before a blood test. Skip a hard workout the day before (exercise and blood tests). Find a nearby Quest site with the lab finder.

What hematocrit is too high on TRT?

Hematocrit is the share of your blood made of red blood cells. Testosterone tells the body to make more of them. Hepcidin, iron handling and erythropoietin all seem to play a part[9]. This rise is the most common lab change on TRT. It is why a CBC is on every monitoring plan.

  • Before starting: a hematocrit above 48% (above 50% at high altitude) is a moderate-to-high risk factor in the Endocrine Society's table[5].
  • On treatment: above 54%, the Endocrine Society says to stop therapy until it falls to a safe level. Next, check for low oxygen and sleep apnea. Then restart at a lower dose[1].
  • In trials: TRAVERSE adjusted doses to keep hematocrit below 54%[10].
  • On labels: if hematocrit becomes elevated, "stop therapy until hematocrit decreases to an acceptable concentration"[6].

How much TRT raises hematocrit, by formulation (percentage points above placebo)

Compared with placebo, cypionate/enanthate injections and oral undecanoate raised mean hematocrit the most; patches the least.

View as table
How much TRT raises hematocrit, by formulation (percentage points above placebo)
GroupValue
Oral undecanoate4.3 pts
Cypionate/enanthate shot4.0 pts
Gel3.0 pts
Undecanoate shot1.6 pts
Patch1.4 pts
Source: [11]

Formulation matters. A network meta-analysis pooled 29 placebo-controlled trials with 3,393 men. Mean hematocrit rose about 4.0 points with cypionate or enanthate injections. It rose 3.0 with gels and 1.4 with patches[11]. Injections raised it more than patches. Other head-to-head gaps were not significant[11]. Reviews agree that short-acting injections carry the highest risk of erythrocytosis[9].

Is a hematocrit of 52% on TRT a problem?

Does donating blood fix high hematocrit on TRT?

Some prescribers order therapeutic phlebotomy, a blood removal procedure done to lower hematocrit. One blood center saw TRT-related phlebotomy orders rise 71.4% over three years[12]. It also found that some men on TRT were showing up as regular blood donors instead[12]. Whether phlebotomy is right for you is a medical decision. The guideline's first steps are to stop treatment for a while and check for sleep apnea. Then restart at a lower dose[1].

When to call your prescriber now

Call promptly if you have a hematocrit above 54% or a confirmed PSA above 4 ng/mL[1]. Also call for new leg swelling or pain, sudden shortness of breath or chest pain. Blood clots in the lungs were more common on testosterone in TRAVERSE[4]. For chest pain, trouble breathing or signs of a stroke, call 911.

What PSA level is concerning on TRT?

Testosterone feeds prostate tissue, so PSA tends to rise a little on TRT. The question is how much. The Endocrine Society refers men to a urologist in four cases: a PSA rise above 1.4 ng/mL within the first 12 months, a confirmed PSA above 4 ng/mL at any time, an abnormal prostate exam, or much worse urinary symptoms[1].

TRAVERSE gives real-world scale. Men with a PSA above 3.0 ng/mL were excluded at entry[13]. On testosterone gel, PSA rose more than on placebo, but only by about 0.11 ng/mL at 3 months and 0.15 ng/mL at 12 months[10]. High-grade prostate cancer was rare: 0.19% vs 0.12%, with no significant difference[13]. Most of the PSA rise comes in year one. A baseline risk check plus a standard plan helps avoid needless biopsies[14].

Do you need estradiol tested on TRT?

Men make estradiol from testosterone. So raising testosterone usually raises estradiol too. Many TRT clinics test it often and treat it with drugs that block estrogen. The guidelines are more limited. The AUA advises an estradiol test before TRT in men with breast symptoms or gynecomastia (breast tissue growth)[3]. The Endocrine Society's monitoring table does not include estradiol[1].

There is a reason for caution about pushing estradiol down. In a controlled study, blocking estradiol in men raised body fat. Low estradiol and low testosterone both lowered sexual function[15]. A major review concluded that estradiol matters for bone, body fat, blood sugar and sexual function in men. It favors testosterone itself over aromatase inhibitors for treating low T[16]. In the Testosterone Trials, bigger estradiol rises tracked bigger gains in bone density and sexual desire. They also tracked a bigger rise in hemoglobin and a bigger drop in HDL[17].

  • Reasonable to test: breast tenderness, swelling or gynecomastia, before or during TRT[3].
  • Weak evidence: routine estradiol checks with dose changes or estrogen blockers aimed at a lab number with no symptoms. No major guideline sets a target estradiol range on TRT.
  • If you test: JustLabs offers estradiol and an ultrasensitive version in the male hormone panel. Read a high estradiol result with your symptoms, not alone.

What else changes on TRT? Lipids, liver, LH/FSH, fertility and the heart

Some lab shifts on TRT are expected. Knowing them ahead of time keeps a normal change from looking like a problem.

  • Hematocrit and hemoglobin rise. This happens with every form of TRT[11].
  • PSA rises a little, mostly in the first year[14].
  • LH and FSH fall. Outside testosterone switches off the pituitary signal. Your body's own testosterone and sperm production drop[8].
  • HDL can fall. In a dose-ranging trial, only a very high 600 mg weekly dose lowered HDL, by about 8 mg/dL. LDL did not change at any dose[7]. The injection label notes that cholesterol may increase[8].
  • Blood pressure can rise. In a 16-week ambulatory study, AndroGel 1.62% raised average blood pressure by 1.9/1.3 mm Hg[6]. In 2025 the FDA added a blood pressure warning to all testosterone products[18].

A lipid panel at baseline and then each year gives you a trend to compare against. If you already have high cholesterol, ask your prescriber how often to recheck.

Does TRT affect fertility and sperm count?

Yes, and this surprises many men. TRT lowers LH and FSH. Those are the signals the testes need to make sperm. The Endocrine Society states plainly that "T therapy suppresses spermatogenesis"[5]. Labels warn that outside testosterone may lead to azoospermia, meaning no sperm in the semen[6]. The Endocrine Society advises against TRT for men planning a pregnancy soon[2]. The AUA includes a fertility evaluation before TRT[3] and has statements for men who want to stay fertile[19].

Is TRT safe for the heart? What TRAVERSE found

TRAVERSE was the large trial built to answer this. It enrolled 5,246 men aged 45 to 80 with heart disease or high heart risk. Each had two fasting testosterone levels under 300 ng/dL. The gel dose was adjusted to keep testosterone between 350 and 750 ng/dL[4]. Over a mean follow-up of 33.0 months, heart attack, stroke or heart death occurred in 7.0% on testosterone and 7.3% on placebo. That met the test for no added risk[4].

TRAVERSE also found more atrial fibrillation, acute kidney injury and blood clots in the lungs on testosterone[4]. On the AndroGel label, venous blood clots occurred in 1.7% vs 1.2%[6]. In 2025 the FDA removed the boxed warning about cardiovascular outcomes. It added TRAVERSE results and a blood pressure warning to all testosterone labels[18]. Bottom line: TRT did not raise major heart events in this trial. Kidney labs in the CMP and blood pressure checks remain part of good monitoring.

Which TRT monitoring tests should you order?

Most follow-up visits need the same core set. That means total and free testosterone drawn at the right time and a CBC for hematocrit. Add PSA if you are in a screening age group, and a CMP and lipid panel once a year. At baseline, add LH/FSH and prolactin if your prescriber is still working out the cause. Add SHBG if total T is borderline. Add estradiol if you have breast symptoms[1][3].

TRT monitoring tests you can order

These are the labs most TRT monitoring plans use. Order the set below or pick single tests. Every order adds one $18 Lab & Physician Order Fee, however many tests you add. You do not need insurance. Results usually arrive in a few days. Share them with your prescriber.

Recommended panel
Male Hormone Panel

$105.50 + $18 order fee · $123.50 all-in

Add panel to cart

Includes 5 tests: Testosterone, Free & Total, Sex Hormone Binding Globulin, DHEA-Sulfate, Cortisol, Total, Estradiol, Ultrasensitive, LC/MS.

The recommended set

$84.50 + one $18 Lab & Physician Order Fee = $102.50 all-in

Add all 6 to cart

No insurance or doctor visit needed: an independent physician issues the order and you are drawn at a Quest center. If a prescriber already monitors you, share this list with them.

Here is how JustLabs works. You order online, visit a Quest Patient Service Center, and get results in your account. One $18 Lab & Physician Order Fee covers each order, however many tests are on it. Many tests are FSA/HSA eligible. Testing is not available in every state. Bring the results to your prescriber, who interprets them with your symptoms and dose history. For more detail on each marker, see TRT monitoring labs: hematocrit, PSA and estradiol.

Frequently asked questions

When should I get blood work on TRT?

Guidelines check testosterone and hematocrit before starting and again 3–6 months after. Hematocrit is then checked every year[1]. The AUA rechecks testosterone every 6–12 months on therapy[3]. Men 55–69, or 40–69 at higher prostate risk, also get PSA before TRT and 3–12 months after starting[1]. A dose change usually triggers an extra check a few months later. Your prescriber sets the exact dates.

Should TRT labs be drawn at trough?

For cypionate or enanthate shots, the Endocrine Society draws testosterone midway between injections, not at trough. It aims for 350–600 ng/dL at that point[1]. Pellets and long-acting undecanoate shots are measured at the end of the interval, which is a trough[1]. Some prescribers prefer trough draws for weekly shots too. What matters most is using the same timing each time so results compare.

What hematocrit is too high on TRT?

The Endocrine Society says to stop TRT if hematocrit is above 54%. Treatment resumes at a lower dose after hematocrit falls and sleep apnea or low oxygen has been checked[1]. Before starting, a hematocrit above 48% (50% at high altitude) is a risk factor[5]. Values between those points are a gray zone. Many prescribers recheck sooner and look at the dose and timing.

Do I need estradiol tested on TRT?

Not routinely, per the main guidelines. The AUA advises estradiol testing before TRT in men with breast symptoms or gynecomastia[3]. The Endocrine Society's monitoring table does not list it[1]. Estradiol helps protect bone and limits body fat gain in men[15][16]. So treating a number without symptoms has weak support. Testing makes sense if you have breast tenderness or swelling.

What PSA level is concerning on TRT?

The Endocrine Society advises a urology consult if PSA rises more than 1.4 ng/mL within the first 12 months. It also advises one for a confirmed PSA above 4 ng/mL at any time[1]. Before starting, a PSA above 4 ng/mL, or above 3 ng/mL in higher-risk men, needs urology review first[2]. In TRAVERSE, the average extra rise on testosterone gel was only about 0.15 ng/mL at 12 months[10].

How often do you need blood work on testosterone?

In the first year, expect labs at baseline and at 3–6 months. Men in PSA age groups have a PSA check between 3 and 12 months[1]. After that, most plans test testosterone every 6–12 months and hematocrit yearly[3][1]. Labels also call for periodic PSA, liver, lipid and blood pressure checks[6]. Any dose or product change usually adds a follow-up test.

When should I test testosterone on TRT injections?

On weekly or every-two-weeks cypionate or enanthate, draw blood midway between shots. That is about day 3–4 on a weekly schedule and day 7 on a two-week schedule. If the mid-interval result is above 600 or below 350 ng/dL, the Endocrine Society suggests adjusting the dose or frequency[1]. A draw the day after a shot catches the peak. It will read higher than the target range is built for.

Why does TRT lower LH and FSH?

Testosterone from outside the body signals the pituitary to stop sending LH and FSH. Labels describe this as feedback inhibition. Your testes then make less of their own testosterone and less sperm[8]. That is why LH and FSH are checked before TRT starts. Once you are on therapy, they are low no matter what caused the original problem[5].

Does TRT raise cholesterol?

It can lower HDL, the "good" cholesterol, mostly at high doses. In one dose-ranging trial, only 600 mg per week lowered HDL, by about 8 mg/dL. LDL did not change at any dose[7]. The injection label notes that cholesterol may increase[8]. Gel labels advise checking lipids periodically[6]. A yearly lipid panel lets you and your prescriber track the trend.

Is TRT bad for your heart?

In the TRAVERSE trial of 5,246 men with heart disease or high heart risk, major heart events occurred in 7.0% on testosterone gel and 7.3% on placebo[4]. The trial did see more atrial fibrillation, acute kidney injury and lung blood clots on testosterone[4]. The FDA later removed the boxed cardiovascular-outcomes warning. It added a blood pressure warning to all testosterone products[18].

Can I order TRT blood work without a doctor visit?

Yes. JustLabs lets you order monitoring tests online and get your blood drawn at a Quest Patient Service Center. An independent physician reviews and signs the order. Each order has one $18 Lab & Physician Order Fee, however many tests you add. No insurance is needed. Testing is not available in every state. Share the results with your TRT prescriber, who makes any treatment decisions.

Keep reading

GuideAnnual Blood Work: Which Tests to Get by Age and Sex (and What Physicals Miss)GuideGLP-1 Blood Work: Labs Before and During Semaglutide or TirzepatideBlogTRT Monitoring Labs: Hematocrit, PSA, and Estradiol TestsGuideHow to prepare for a blood test

Sources

  1. Endocrine Society (Bhasin S, et al.). Testosterone Therapy in Men With Hypogonadism: An Endocrine Society Clinical Practice Guideline. J Clin Endocrinol Metab. 2018;103(5):1715-1744. Full text, Table 9: Monitoring men receiving testosterone therapy. Source
  2. Bhasin S, Brito JP, Cunningham GR, Hayes FJ, Hodis HN, Matsumoto AM, Snyder PJ, Swerdloff RS, Wu FC, Yialamas MA. Testosterone Therapy in Men With Hypogonadism: An Endocrine Society Clinical Practice Guideline. J Clin Endocrinol Metab. 2018 May 1;103(5):1715-1744. doi: 10.1210/jc.2018-00229. PMID: 29562364. PubMed
  3. Urology Times (Clarke H). Testosterone deficiency: FAQs from the AUA guideline. July 30, 2026. Source
  4. Lincoff AM, Bhasin S, Flevaris P, Mitchell LM, Basaria S, Boden WE, Cunningham GR, Granger CB, Khera M, Thompson IM Jr, Wang Q, Wolski K, Davey D, Kalahasti V, Khan N, Miller MG, Snabes MC, Chan A, Dubcenco E, Li X, Yi T, Huang B, Pencina KM, Travison TG, Nissen SE, TRAVERSE Study Investigators. Cardiovascular Safety of Testosterone-Replacement Therapy. N Engl J Med. 2023 Jul 13;389(2):107-117. doi: 10.1056/NEJMoa2215025. PMID: 37326322. PubMed
  5. Endocrine Society (Bhasin S, et al.). Testosterone Therapy in Men With Hypogonadism: An Endocrine Society Clinical Practice Guideline. J Clin Endocrinol Metab. 2018;103(5):1715-1744. Full text, sections 1–2 and Tables 2 and 7. Source
  6. U.S. National Library of Medicine, DailyMed. ANDROGEL (testosterone gel) 1.62%, Ascend Therapeutics U.S., LLC: prescribing information. Updated Nov 17, 2025. Source
  7. Singh AB, Hsia S, Alaupovic P, Sinha-Hikim I, Woodhouse L, Buchanan TA, Shen R, Bross R, Berman N, Bhasin S. The effects of varying doses of T on insulin sensitivity, plasma lipids, apolipoproteins, and C-reactive protein in healthy young men. J Clin Endocrinol Metab. 2002 Jan;87(1):136-43. doi: 10.1210/jcem.87.1.8172. PMID: 11788637. PubMed
  8. U.S. National Library of Medicine, DailyMed. DEPO-Testosterone (testosterone cypionate) injection, Pharmacia & Upjohn Company LLC: prescribing information. Updated Aug 20, 2026. Source
  9. Ohlander SJ, Varghese B, Pastuszak AW. Erythrocytosis Following Testosterone Therapy. Sex Med Rev. 2018 Jan;6(1):77-85. doi: 10.1016/j.sxmr.2017.04.001. PMID: 28526632. PubMed
  10. Bhasin S, et al. Prostate Safety Events During Testosterone Replacement Therapy in Men With Hypogonadism: A Randomized Clinical Trial. JAMA Netw Open. 2023;6(12):e2348692. Full text (PMC10753401), Methods and Results. Source
  11. Nackeeran S, Kohn T, Gonzalez D, White J, Ory J, Ramasamy R. The Effect of Route of Testosterone on Changes in Hematocrit: A Systematic Review and Bayesian Network Meta-Analysis of Randomized Trials. J Urol. 2022 Jan;207(1):44-51. doi: 10.1097/JU.0000000000002188. PMID: 34445892. PubMed
  12. Van Buren NL, Hove AJ, French TA, Gorlin JB. Therapeutic Phlebotomy for Testosterone-Induced Polycythemia. Am J Clin Pathol. 2020 Jun 8;154(1):33-37. doi: 10.1093/ajcp/aqaa019. PMID: 32134468. PubMed
  13. Bhasin S, Travison TG, Pencina KM, O'Leary M, Cunningham GR, Lincoff AM, Nissen SE, Lucia MS, Preston MA, Khera M, Khan N, Snabes MC, Li X, Tangen CM, Buhr KA, Thompson IM Jr. Prostate Safety Events During Testosterone Replacement Therapy in Men With Hypogonadism: A Randomized Clinical Trial. JAMA Netw Open. 2023 Dec 1;6(12):e2348692. doi: 10.1001/jamanetworkopen.2023.48692. PMID: 38150256. PubMed
  14. Bhasin S, Thompson IM. Prostate Risk and Monitoring During Testosterone Replacement Therapy. J Clin Endocrinol Metab. 2024 Jul 12;109(8):1975-1983. doi: 10.1210/clinem/dgae334. PMID: 38753865. PubMed
  15. Finkelstein JS, Lee H, Burnett-Bowie SA, Pallais JC, Yu EW, Borges LF, Jones BF, Barry CV, Wulczyn KE, Thomas BJ, Leder BZ. Gonadal steroids and body composition, strength, and sexual function in men. N Engl J Med. 2013 Sep 12;369(11):1011-22. doi: 10.1056/NEJMoa1206168. PMID: 24024838. PubMed
  16. Russell N, Grossmann M. MECHANISMS IN ENDOCRINOLOGY: Estradiol as a male hormone. Eur J Endocrinol. 2019 Jul;181(1):R23-R43. doi: 10.1530/EJE-18-1000. PMID: 31096185. PubMed
  17. Stephens-Shields AJ, Snyder PJ, Ellenberg SS, Taylor L, Bhasin S. Relation of Testosterone, Dihydrotestosterone, and Estradiol With Changes in Outcomes Measures in the Testosterone Trials. J Clin Endocrinol Metab. 2022 Apr 19;107(5):1257-1269. doi: 10.1210/clinem/dgac028. PMID: 35041751. PubMed
  18. U.S. Food and Drug Administration. FDA issues class-wide labeling changes for testosterone products. February 28, 2025. Source
  19. Mulhall JP, Trost LW, Brannigan RE, Kurtz EG, Redmon JB, Chiles KA, Lightner DJ, Miner MM, Murad MH, Nelson CJ, Platz EA, Ramanathan LV, Lewis RW. Evaluation and Management of Testosterone Deficiency: AUA Guideline. J Urol. 2018 Aug;200(2):423-432. doi: 10.1016/j.juro.2018.03.115. PMID: 29601923. PubMed

Content reviewed for accuracy by the JustLabs editorial team.

Educational information, not medical advice. Don’t start, change or stop a medicine based on this guide: talk to your prescriber. Lab results are interpreted by a clinician who knows your full history; if you have severe symptoms, seek care right away.