Proper preparation before thyroid lab testing helps ensure accurate results and effective thyroid optimization. This guide outlines key steps to take before your labs so your provider can make informed, personalized treatment decisions.
Before You Go for Your Labs:
To ensure accurate and consistent results, please follow these guidelines unless otherwise directed by your provider:
- Timing of Collection
- All required lab work must be completed 7–10 days prior to your scheduled telehealth appointment to ensure results are available for review. Appointments may need to be rescheduled if labs are not received in time.
- Schedule your blood draw in the morning between 8:00–10:00 AM
- For consistency, try to use the same lab and timing for future draws when possible.
- Fasting
- Please fast for at least 8 hours before your lab draw
- Water, black coffee, or plain tea (no cream or sugar) are permitted
- Avoid supplements, protein shakes, or caloric beverages until after your draw.
- Medication Instructions
- Thyroid medication (Levothyroxine, Liothyronine, or NDT):
Do not take your thyroid medication before your lab draw.
Wait to take it until after your blood has been drawn to prevent falsely elevated hormone levels. - Other medications: Continue as prescribed unless instructed otherwise by your provider.
- Hormone or peptide therapies: Skip your morning dose until after your lab draw, if applicable.
- Thyroid medication (Levothyroxine, Liothyronine, or NDT):
- Hydration
- Drink plenty of water the day before and morning of your lab draw.
- Proper hydration helps improve blood flow and accuracy of kidney and metabolic markers.
- Exercise & Alcohol
- Avoid strenuous exercise, high-intensity training, or alcohol consumption for 24 hours before your lab draw, as these can influence thyroid values.
