How to prepare for a blood draw

A little preparation makes your results more accurate and your visit faster. Here's a short checklist.

Fast if your test requires it

Lipid panels, glucose, and some others ask for a 9–12 hour fast — water is fine, and usually encouraged. Your order confirmation lists fasting requirements for each test, so check before you go.

Hydrate

Drink water beforehand (unless told otherwise). Well-hydrated veins are easier to draw from, which means a quicker, more comfortable stick.

Time it consistently

Some markers — cortisol, testosterone, iron — vary across the day. If you're tracking a value over time, draw at roughly the same time of day each visit so you're comparing like with like.

The day of

• Bring a photo ID and your requisition (we email it and store it in your account).
• Wear short sleeves or sleeves that roll up easily.
• Mention any medications or supplements, since some (like biotin) can affect certain assays.

That's it — most draws take just a few minutes.

This article is for general education and is not medical advice. Consult a qualified healthcare provider about your results. Read about how we write about lab testing.