What lab tests are required before starting hormone replacement therapy?

Laboratory Tests Required Before Starting Hormone Replacement Therapy

Blood pressure measurement is the only mandatory test required before initiating hormone replacement therapy in healthy women, though comprehensive baseline testing including thyroid function, complete blood count, metabolic panel, lipid profile, and hormone levels is recommended for optimal monitoring. 1

Mandatory Testing (Class A - Essential)

• Blood pressure measurement is the sole essential examination required before starting HRT, as severe hypertension (≥160/100 mmHg) represents an absolute contraindication and moderate hypertension (140-159/90-99 mmHg) is a relative contraindication 1
• Blood pressure can be obtained in non-clinical settings (pharmacy, fire station) if healthcare access is limited and self-reported to the provider 1

Recommended Comprehensive Baseline Testing

While not mandatory for healthy women, the following tests optimize monitoring and safety 2, 1:

Metabolic and Organ Function Tests

• Comprehensive Metabolic Panel including liver function tests, kidney function, electrolytes, and fasting blood glucose to assess overall health status 2
• Complete Blood Count (CBC) to monitor potential effects on blood cell counts 2
• Lipid Profile including total cholesterol, HDL, LDL, and triglycerides for cardiovascular risk assessment 2

Endocrine Function Tests

• Thyroid function tests: TSH and free thyroxine (free T4) to evaluate thyroid status 2
• Hormone-specific testing depends on the type of HRT:
  • For feminizing HRT: baseline estradiol and testosterone levels 2
  • For masculinizing HRT: baseline testosterone and estradiol levels 2
• Prolactin levels only if symptoms suggest hyperprolactinemia or pituitary dysfunction—not routinely 1

Additional Risk-Based Testing

• HbA1c and fasting glucose for patients with diabetes or at risk for diabetes 2

Tests NOT Required for Healthy Women

The following tests are unnecessary unless specific risk factors are present 1:

• Glucose testing (unless diabetes risk factors present)
• Thrombogenic mutation screening
• Cervical cytology
• Clinical breast examination
• Bimanual examination
• Cervical inspection
• STD/HIV screening

Monitoring Schedule After Initiation

• Initial follow-up: Repeat laboratory tests at 3 months after starting HRT to assess response and adjust dosing 2, 1
• First year: Monitor every 3-6 months 2, 1
• Long-term: Annual monitoring if stable 2, 1

Critical Testing Considerations and Pitfalls

Timing and Interpretation

• Testosterone monitoring must be performed in the morning due to diurnal variation 2, 1
• After 1 year of gender-affirming hormone therapy, interpret most laboratory values using the affirmed gender reference ranges 1

Medication-Specific Monitoring

• Liver function tests are particularly important with oral estrogen formulations, though low-dose estrogen shows minimal hepatic effects 1
• Electrolyte monitoring (sodium, potassium, BUN) is essential for patients receiving spironolactone as part of feminizing therapy 1

Common Errors to Avoid

• Do not perform routine prolactin testing—only test if symptoms suggest hyperprolactinemia or pituitary dysfunction 1
• Do not delay HRT initiation for extensive testing in healthy women—blood pressure is the only mandatory requirement 1
• Do not forget morning timing for testosterone measurements, as levels vary significantly throughout the day 2, 1