Some medications can affect blood lab results. Others should not be stopped. The guidance below explains what to pause, what to continue, and how to time your labs — so your results accurately reflect your baseline and can be interpreted with confidence.
Always follow your prescribing clinician’s instructions if they differ from the guidance below.
Birth Control Pills
If you're taking oral contraceptive pills, do not stop active pills mid-cycle.
Instead, plan your blood draw during the placebo (non-active) days of your pill pack.
How to time it:
If your pack has 4 placebo days: schedule your blood draw on day 2 or later of placebo
If your pack has 2 placebo days: schedule your blood draw on day 2 of placebo
This timing helps your results reflect your baseline hormone patterns more accurately.
Corticosteroids (Steroids)
Short-Term Steroid Prescriptions
If you’ve taken a short course of steroids (such as prednisone for an acute issue):
Wait at least two weeks after your final dose before completing blood labs
This allows hormone and inflammatory markers to return closer to baseline.
Ongoing Steroid Use
This includes prescription or over-the-counter forms such as:
Topical creams (for example, hydrocortisone)
Inhalers or nasal sprays
Oral steroids used long-term
If it is safe to pause:
Stop the medication the day before and the day of your blood draw
If you cannot pause the medication:
Continue taking it as usual
Let your provider know at your visit so your results can be interpreted appropriately
If you’re unsure whether it’s safe to pause a medication, consult your prescribing clinician or pharmacist — and follow their guidance.
Medications You Should Continue
Continue the following unless your provider has specifically told you otherwise:
Progesterone (oral)
If taken at night, it clears quickly and will not affect your morning blood draw.DHEA
Continue taking DHEA as prescribed. Your provider reviews your results while you’re on it to determine whether to maintain or adjust your dose.All other prescribed medications
Continue as usual unless you’ve been instructed differently.
What If My Medication Says “Take With Food”?
If your medication must be taken with food:
Schedule an early-morning blood draw
Bring your medication with you
Take it right after your blood draw, with a small snack
If you take diabetes medications or insulin, or if delaying a dose may be unsafe, contact your prescribing clinician for guidance. If they advise eating beforehand, let your provider know at your visit so your results can be interpreted accordingly.
Why This Matters
Certain medications can temporarily influence hormone, metabolic, or inflammatory markers. Following these guidelines helps your provider:
Interpret results accurately
Avoid misleading patterns
Make safer, more precise recommendations