How to Prepare for a DEXA Scan

What to Wear

Wear athletic clothing without metal. T-shirt, shorts, leggings, or joggers work well. Avoid:

• Zippers, snaps, or belt buckles
• Underwire bras (sports bras are fine)
• Jewelry -- rings are okay, but remove necklaces and watches
• Clothing with metallic threads or foil prints

Metal interferes with the X-ray beams and can distort your results. If you forget and show up in jeans, it's not the end of the world -- but athletic wear gives the cleanest scan.

Food and Water

You don't need to fast before a DEXA scan. But for the most consistent results -- especially if you're tracking changes over time -- try to:

• Avoid eating a large meal within 2 hours of your scan
• Stay normally hydrated (don't chug water right before, but don't dehydrate yourself either)
• Avoid creatine loading in the days before if you're tracking lean mass precisely (creatine pulls water into muscle tissue, which DEXA reads as lean mass)

These factors have a small effect on any single scan. They matter more when you're comparing scans over time and want consistency.

Exercise

Avoid intense exercise within a few hours of your scan. A hard workout shifts fluid from your blood into your muscles (the "pump"), which can slightly inflate lean mass readings and skew body fat percentage.

A morning walk or light activity is fine. Just don't come straight from a heavy leg session.

Timing and Consistency

If you plan to scan regularly to track progress, consistency matters more than perfection. Try to:

• Scan at roughly the same time of day
• Scan in a similar hydration and fed state
• Use the same facility and scanner each time

Body weight fluctuates 2-4 lbs throughout the day from water and food. Scanning under similar conditions each time reduces noise in your data.

What Happens During the Scan

You lie flat on an open table -- no enclosed tube, no loud noises. A scanning arm passes over your body for about 7-10 minutes. The radiation dose is extremely low, comparable to a few hours of natural background radiation.

The whole visit -- check-in and scan -- takes about 15-20 minutes.

Who Should Not Get a DEXA Scan

DEXA scans use a very small amount of radiation and are considered safe for routine use. However, you should not get a DEXA scan if you are pregnant or think you might be pregnant. If you've had a barium or contrast study in the past week, let your technician know -- residual contrast material can affect results.

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