What laboratory tests are required to monitor patients receiving testosterone (hormone replacement therapy) for transgender care?

From the Guidelines

For transgender patients receiving testosterone therapy, regular laboratory monitoring should include complete blood count (CBC), liver function tests (LFTs), lipid panel, and testosterone levels, as well as hemoglobin and hematocrit to monitor for polycythemia and assess the need for dose adjustment or therapeutic phlebotomy 1.

Laboratory Monitoring

The following laboratory tests are essential for monitoring patients on testosterone therapy:

• Complete blood count (CBC) to monitor for polycythemia (elevated red blood cell count), a common side effect of testosterone therapy that can increase thrombosis risk 1
• Liver function tests (LFTs) to detect potential hepatotoxicity
• Lipid panel to track changes in cholesterol levels, as testosterone may decrease HDL and increase LDL cholesterol 1
• Testosterone levels to ensure they remain in the male physiologic range (typically 300-1000 ng/dL), with trough levels checked just before the next dose for injectable formulations 1
• Hemoglobin and hematocrit to monitor for polycythemia and assess the need for dose adjustment or therapeutic phlebotomy, with values exceeding 54% requiring intervention 1

Additional Monitoring

For patients with risk factors, additional monitoring may be necessary, including:

• Fasting glucose or hemoglobin A1c to assess insulin sensitivity
• Kidney function tests, particularly in patients with pre-existing conditions

Frequency of Monitoring

These laboratory tests are typically performed every 3 months during the first year of therapy and then every 6-12 months thereafter if values remain stable, though frequency should be individualized based on patient factors and clinical response 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.

• Key labs to monitor in patients receiving testosterone therapy include:
  • Hemoglobin and hematocrit levels to detect polycythemia
  • Serum cholesterol levels These labs should be checked periodically in patients receiving long-term androgen administration 2.

From the Research

Laboratory Monitoring for Testosterone Therapy in Transgender Patients

To minimize risks associated with testosterone therapy in transgender patients, regular laboratory monitoring is essential. The following labs should be monitored:

• Hematocrit (Hct) levels to check for polycythemia, a common adverse effect of testosterone replacement therapy 3, 4, 5
• Hemoglobin (Hb) levels to assess the risk of venothromboembolism (VTE) 4, 5
• Plasma testosterone levels to ensure they remain within male physiological ranges (300 to 1,000 ng/dl) during hormonal treatment 6
• Other metabolic indices, such as bone and cardiovascular health markers, to monitor the effects of long-term hormone therapy 7

Monitoring Schedule

The monitoring schedule for transgender patients on testosterone therapy may vary, but it is recommended to:

• Monitor patients every 3 months during the first year of treatment 6
• Monitor patients every 6 to 12 months after the first year of treatment 6
• Regularly assess hematocrit levels to prevent polycythemia and reduce the risk of vascular events 3, 4, 5

Considerations for Treatment

When considering treatment for transgender patients on testosterone therapy, it is essential to:

• Choose appropriate candidates for hormone therapy based on existing guidelines 7
• Select treatment regimens that minimize the risk of adverse effects, such as polycythemia 3, 5
• Monitor patients regularly to adjust treatment regimens as needed and prevent long-term complications 6, 7