From the Guidelines
For someone with low testosterone, the primary lab tests to monitor regularly include total testosterone, free testosterone, complete blood count (CBC), lipid panels, prostate-specific antigen (PSA) testing, estradiol levels, luteinizing hormone (LH) and follicle-stimulating hormone (FSH) levels, liver function tests, and hemoglobin A1c or fasting glucose tests. These tests are essential for evaluating the effectiveness of treatment and monitoring potential side effects, as recommended by the most recent guidelines 1.
Key Lab Tests
- Total testosterone: measures the overall amount of testosterone in the blood, with follow-up testing typically done every 3-6 months after starting treatment and then annually once levels stabilize 1
- Free testosterone: represents the biologically active hormone not bound to proteins, and should be measured in men with total testosterone levels close to the lower limit 1
- Complete blood count (CBC): important to monitor for polycythemia (increased red blood cell production), a potential side effect of testosterone therapy
- Lipid panels: track cholesterol levels which can be affected by hormone treatment
- Prostate-specific antigen (PSA) testing: crucial for men over 40 to monitor prostate health, as testosterone therapy may impact prostate growth 1
- Estradiol levels: should be checked since testosterone can convert to estrogen, potentially causing side effects
- Luteinizing hormone (LH) and follicle-stimulating hormone (FSH) levels: help determine if low testosterone is primary (testicular) or secondary (pituitary/hypothalamic) 1
- Liver function tests: monitor for potential liver stress from certain testosterone formulations
- Hemoglobin A1c or fasting glucose tests: recommended since testosterone affects insulin sensitivity and glucose metabolism 1
Monitoring Schedule
The monitoring schedule for these lab tests may vary depending on individual patient needs and treatment plans. However, as a general guideline, follow-up testing is typically done every 3-6 months after starting treatment and then annually once levels stabilize 1.
Importance of Regular Monitoring
Regular monitoring of these lab tests is crucial for ensuring the safe and effective treatment of low testosterone. By tracking changes in testosterone levels, prostate health, and other potential side effects, healthcare providers can adjust treatment plans as needed to minimize risks and optimize benefits for patients 1.
From the FDA Drug Label
Laboratory tests: Hemoglobin and hematocrit levels (to detect polycythemia) should be checked periodically in patients receiving long-term androgen administration. Serum cholesterol may increase during androgen therapy. The lab tests to monitor for someone with low testosterone receiving testosterone replacement therapy are:
- Hemoglobin and hematocrit levels to detect polycythemia
- Serum cholesterol levels 2
From the Research
Lab Tests to Monitor for Someone with Low Testosterone
To monitor someone with low testosterone, the following lab tests are recommended:
- Testosterone levels: Measuring testosterone levels is crucial in diagnosing and managing low testosterone 3, 4.
- Liver function tests: Tests such as alanine transaminase (ALT), aspartate transaminase (AST), and gamma-glutamyl-transferase (γ-GT) can help monitor liver function, which can be affected by low testosterone and testosterone replacement therapy 5, 6.
- Lipid profiles: Monitoring lipid profiles, including low-density lipoprotein (LDL) and high-density lipoprotein (HDL), is essential as low testosterone and testosterone replacement therapy can affect lipid levels 5, 7, 6.
- Fatty Liver Index (FLI): Calculating the FLI according to Mayo Clinic guidelines can help assess hepatic steatosis and monitor the effectiveness of testosterone replacement therapy 5, 6.
- Blood glucose and hemoglobin A1c: Monitoring blood glucose and hemoglobin A1c levels can help assess the risk of developing type 2 diabetes mellitus, which is often associated with low testosterone 5, 6.
- Complete blood count (CBC): A CBC can help monitor for any adverse effects of testosterone replacement therapy on blood cell production 4.
Frequency of Lab Tests
The frequency of lab tests may vary depending on the individual's condition and the specific treatment plan. However, it is generally recommended to:
- Monitor testosterone levels regularly to ensure that they are within the normal range 3, 4.
- Perform liver function tests and lipid profiles at regular intervals to monitor for any adverse effects of testosterone replacement therapy 5, 7, 6.
- Calculate the FLI and monitor blood glucose and hemoglobin A1c levels regularly to assess the effectiveness of testosterone replacement therapy and monitor for any potential risks 5, 6.