Testosterone replacement therapy (TRT) is a medical treatment used to address low testosterone levels in men. Before initiating TRT, doctors conduct blood tests to measure total and free testosterone levels and evaluate symptoms such as low sex drive, erectile dysfunction, fatigue, low mood, and cognitive issues. Once TRT is underway, regular monitoring through blood tests is essential to ensure optimal outcomes and minimize potential side effects. This article explores the importance of blood tests in monitoring TRT, highlighting key values to consider for maximizing benefits and preventing complications.

Blood Tests for Initial Assessment and Treatment Selection

Before initiating TRT, doctors rely on blood tests to assess testosterone levels and evaluate symptoms. Measuring total and free testosterone levels provides crucial information about hormone deficiencies. Additionally, asking patients about their symptoms helps identify possible signs of low testosterone. Based on these findings, doctors can determine the appropriate treatment approach for each individual.

 Methods of Testosterone Replacement Therapy

TRT can be administered using various methods, including injections, creams, gels, pellets, and nasal gels. The choice of method depends on factors such as patient preference, convenience, and specific medical considerations. The doctor's expertise is crucial in selecting the most suitable TRT option to ensure optimal results.

Follow-Up Blood Tests and Dosage Adjustments

Once TRT has commenced, regular follow-up blood tests are conducted around weeks six or eight. These tests help evaluate the effectiveness of the treatment and determine if any adjustments to dosage or additional medications are necessary. For instance, estradiol modulation may be required to maintain hormonal balance. Monitoring hormone levels through blood tests enables doctors to fine-tune treatment plans and ensure that patients receive the most beneficial outcomes from TRT.

Monitoring Testosterone Levels

Monitoring testosterone levels is a critical aspect of TRT. The target total testosterone level for men on TRT is typically above 500 nanograms per deciliter. If the measured level falls below this threshold, adjustments to dosage or injection frequency may be necessary to achieve optimal hormone balance.

Importance of Free Testosterone and Sex Hormone-Binding Globulin (SHBG)

Besides total testosterone, free testosterone levels are also significant. Free testosterone represents the portion of testosterone that is readily available for biological activity. Ideally, free testosterone should be around 2% of the total testosterone or higher. Lower levels may indicate issues related to sex hormone-binding globulin (SHBG), a protein that binds to testosterone and reduces its availability for use. Monitoring free testosterone levels helps doctors identify and address any SHBG-related concerns to optimize TRT outcomes.

Monitoring Hematocrit Levels

Hematocrit levels, which measure the proportion of red blood cells in the blood, should be monitored during TRT. Testosterone replacement can increase red blood cell count in some individuals. Elevated hematocrit levels can lead to increased blood viscosity and potential cardiovascular issues. To mitigate these risks, the ideal hematocrit range during TRT is below 53. Regular monitoring of hematocrit levels allows doctors to identify any concerns and take appropriate measures to maintain cardiovascular health.

PSA Levels and Prostate Health

Prostate-specific antigen (PSA) levels play a crucial role in monitoring prostate health during TRT. Men with a PSA level of four or higher require careful evaluation, as it may indicate prostate-related concerns, including the possibility of prostate cancer. Further investigation and consultation with a urologist are usually recommended for individuals with high PSA levels. Monitoring PSA levels is vital to ensuring the safe and effective administration of TRT.

Balancing Estradiol Levels

Estradiol, a form of estrogen, plays a significant role in men's health and well-being. Balancing estradiol levels is essential to maximizing the benefits of TRT. Very low or high estradiol levels can have negative effects on mood, cognition, cardiovascular health, sex drive, and body composition. The optimal range for estradiol levels provided by lab companies in men typically falls between 20 and 40 picograms per milliliter. However, this range does not apply to men with high testosterone blood levels caused by TRT. Regular monitoring of estradiol levels allows doctors to ensure hormonal balance and adjust treatment if necessary.

Monitoring Blood Pressure

Blood pressure monitoring is essential during TRT, as some men may experience increases in blood pressure due to hormonal changes. Lifestyle modifications such as weight loss, regular exercise, and medication can help manage blood pressure levels effectively. Regular blood pressure monitoring allows doctors to identify any changes and implement appropriate interventions to maintain cardiovascular health.

Kidney Function (eGFR) Assessment

Assessing kidney function is an important aspect of monitoring TRT. Estimated glomerular filtration rate (eGFR) is a measure used to evaluate kidney function. Contrary to common misconceptions, TRT itself does not cause a decrease in eGFR. Regular assessments of kidney function help ensure the safety and effectiveness of TRT by identifying any potential renal complications.

Monitoring Liver Enzymes

Liver enzyme levels, such as aspartate transaminase (AST) and alanine transaminase (ALT), should be monitored during TRT. It is important to note that TRT has not been shown to increase liver enzymes. However, men who engage in heavy weightlifting exercises may experience artificial increases in AST and ALT levels, which are unrelated to TRT or liver toxicity. Proper interpretation of liver enzyme levels is crucial to avoid unnecessary concerns or interventions.

Thyroid Function Assessment

Thyroid function should be monitored during TRT to ensure overall hormonal balance. Thyroid-stimulating hormone (TSH) levels are typically measured to evaluate thyroid function. A TSH level below 2.5 is indicative of a healthy thyroid. Further tests, such as measuring free triiodothyronine (T3) and free thyroxine (T4), may be conducted to assess thyroid function more comprehensively. Monitoring thyroid function allows doctors to address any thyroid-related issues that may impact TRT outcomes.

Checking Iron Levels

Regular monitoring of iron levels is important, particularly for individuals who frequently donate blood. Frequent blood donations can deplete iron stores, leading to fatigue and other related symptoms. To maintain optimal iron levels, individuals undergoing TRT should ensure that donation frequency aligns with recommended guidelines. If iron levels are found to be low, supplementation may be necessary to mitigate fatigue and maintain overall well-being.

Monitoring HDL Cholesterol Levels

High-density lipoprotein (HDL) cholesterol levels can be affected by TRT, especially at higher doses. Higher doses of testosterone replacement therapy may lead to a decrease in HDL cholesterol, which is a concern for cardiovascular health. Regular monitoring of lipid levels, including HDL cholesterol, allows doctors to assess cardiovascular risk and consider interventions such as niacin supplementation to manage HDL levels effectively.

Assessing Prolactin Levels

Prolactin levels are typically checked in men with very low testosterone levels or those who do not respond well to TRT. Elevated prolactin levels may indicate underlying issues that could impact the effectiveness of TRT. While prolactin is commonly associated with lactation in women, men also produce this hormone, and imbalances can lead to complications such as erectile dysfunction. Monitoring prolactin levels helps doctors ensure optimal treatment response for individuals undergoing TRT.

Affordable Blood Testing Services and Additional Resources

Discountedlabs.com offers affordable blood testing services, including the necessary tests for monitoring TRT labs. The website provides various blood test options, and results are typically delivered within five to seven business days. Additionally, Excel mail.com offers further information and resources on blood tests and TRT, including a blog page and a resources including a free downloadable book titled "Beyond Testosterome." These resources can help individuals educate themselves, better understand their blood test results, and make informed decisions about their TRT journey.


Monitoring TRT through regular blood tests is crucial for maximizing the benefits and preventing potential side effects. Key values to consider during blood tests include total and free testosterone levels, hematocrit levels, PSA levels, estradiol levels, blood pressure, kidney function, liver enzymes, thyroid function, iron levels, HDL cholesterol levels, and prolactin levels. Affordable blood testing services like Discountedlabs.com and resources from Excel mail.com provide individuals undergoing TRT with accessible options for monitoring their hormone levels effectively. Regular communication with healthcare professionals is vital to tailor TRT treatment and ensure its safety and efficacy. By monitoring key values through blood tests, individuals can optimize the benefits of TRT and enhance their overall well-being.