Guide

Many glucose blood tests require an 8–12 hour food fast, while A1C and random glucose tests usually don’t.

Many lipid checks work fine without fasting; fasting is requested when triglycerides need a cleaner baseline or a prior result looked high.

Most MRI scans let you eat and drink normally, yet some exams ask for a short fast when abdominal imaging or sedation affects the pictures.

No—most PSA blood draws don’t require fasting, unless your lab bundles PSA with other tests that do.

No—most PSA blood tests don’t require fasting, so you can eat and drink normally unless your order includes other tests that do.

Most testosterone blood tests don’t require fasting, but many labs prefer a morning, fasting sample when testosterone is checked for diagnosis.

Yes, a small serving can fit your plan when you count carbs, limit added sugar, and check glucose after.

Most thyroid blood tests don’t require fasting; eat normally unless your order also includes tests like glucose or cholesterol that do.

No, an A1C blood test usually doesn’t require fasting; eat and drink as usual unless your order includes other labs.

Fasting usually isn’t required for a TSH blood draw, but take thyroid medicine and supplements exactly as your lab instructions say.