Fasting Labs 101: How to Prepare (and What ‘Fasting’ Really Means)

Many common lab tests require fasting, but instructions can be confusing. Here’s a clear, practical guide to help you show up prepared.

What counts as fasting?

Typically, fasting means no food for 8–12 hours. Water is usually allowed (and encouraged). Coffee, gum, and supplements may affect results—follow your provider’s instructions.

Quick checklist

• Confirm fasting window (8–12 hours).

• Drink water unless told otherwise.

• Bring your lab order and ID.

CTA: Need fasting labs done at home? Book a morning appointment with OnGo Diagnostics.