How to Prepare for a Blood Test?

Follow these guidelines for accurate and consistent results.

Schedule your lab test as the first thing in the morning. Blood draws should ideally occur 2-3 hours after waking.

10 days before the test:

  • ⚠️
    Be sure to complete any prescribed courses of antibiotics, antiparasitics, and antifungals as directed by your doctor.
  • 💊
    Start tapering off supplements
    Continue taking any medications prescribed by your doctor, but start tapering off all supplements and non-prescription drugs. This includes electrolytes, vitamins, minerals, powders, recreational drugs, and over-the-counter medications.

3 days before the test:

  • 🏋️‍♂️
    Avoid strenuous activities such as strength training. During this period, engage only in light activities.
  • ⚕️
    If possible, discontinue the use of aspirin and other NSAIDs (such as ibuprofen, etc.).
  • 💊
    You should not be taking any supplements at this point.

Day before the test:

  • 💪
    If you experience severe muscle soreness, reschedule the test.
  • 🍽️
    Eat a balanced diet, ensuring it's not overly high in proteins, fats, or carbohydrates.
  • ⏳
    Have your last light meal about 12 hours before the blood test, but no less than 10 hours and no more than 15 hours before the test.
  • 🍷
    Do not drink any alcohol.

On the morning of the test:

  • 🥛
    In the morning, drink plain water as follows:
    • 📌
      500 ml of water two hours before the blood test
    • or
    • 📌
      300 ml of water one hour before the blood test.
  • 🚫
    Do not eat anything. Apart from water, do not consume anything else, including coffee, tea, or gum.
  • 🧘‍♂️
    Avoid stress and stimulants, such as work-related stress, cold showers, etc.
  • 🚬
    Nicotine affects blood markers for up to 12 hours. If you smoke, wait until after the test.

About the site author

My personal mission is to extend human lifespan by collectively adding 1 million years to people's lives.

Zsolt Szabo
Zsolt Szabo
Software Engineer, Biohacker, and Consultant for Longevity Clinics.

Please send me studies and feedback.

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I am particularly interested in research on biomarkers linked to all-cause mortality or optimal reference ranges.