You’ve booked your DEXA scan, you’re walking out the door, and someone tells you “no metal.” Easy enough. Then you get to the studio and realize your sports bra has an underwire, your jeans have rivets, and there’s a hair clip you forgot about. Here’s exactly why metal during a DEXA scan matters, and the simple list of what to wear and what to skip.

What metal actually does to a DEXA scan

DEXA uses two low-energy X-ray beams. Different tissues attenuate the beams predictably — fat one way, muscle another, bone yet another. The scanner’s software classifies each pixel based on the attenuation pattern.

Metal does something the software doesn’t expect. It absorbs both beams almost completely, creating a region of “saturation” in the data. Depending on the algorithm, that region either gets classified as very dense bone or as a measurement error. Either way, the surrounding tissue numbers shift slightly to compensate.

For a one-off scan, that’s annoying but not catastrophic. For tracking over time, it’s a problem — different clothes between scans means different artifacts, which means your scan-to-scan changes might be measurement, not real change.

The most common offenders

Underwire bras

The single most common DEXA scan disaster. Underwires sit right across the chest where rib density is being measured. Removes them and the scan reads cleanly.

Jeans

Metal rivets, zipper, and the metal button. All show up. Athletic shorts are the easy fix.

Hair clips and bobby pins

These tend to be forgotten because they’re hidden in your hair. Pull them out before the scan.

Watches and fitness trackers

Both metal cases and bands. Take them off and put them with your other things.

Jewelry

Necklaces and large rings show up clearly. Stud earrings are usually small enough to be a non-issue but the big hoop earrings will read.

Belt buckles

If you forgot to swap into shorts and you’re wearing a belt — pull the belt off entirely.

Bras with metal closures or hooks

Even non-underwire bras sometimes have metal closures. Sports bras with no closures or hooks are safest.

What to wear instead

• Athletic shorts — no metal at all.
• Metal-free sports bra — pull-on style, no closures.
• Thin t-shirt or tank — cotton or moisture-wicking, no graphics with metallic ink.
• Plain leggings — most are metal-free; double-check the waistband.

If your scan-to-scan results jump in unexpected directions, the first thing we check is whether you wore the same outfit. Bra changes alone can shift trunk-fat readings by 1–2%.

Studio prep, in order

1. At home: wear or pack metal-free clothes.
2. At the studio: change into the prepared outfit if you weren’t already wearing it. We have a private changing area.
3. Empty pockets: phone, keys, coins, wallet — all out.
4. Remove jewelry: watch, rings (some can stay if small), necklaces, earrings.
5. Hair check: pull out any metal clips or pins.
6. Lie down for the scan: we’ll position you and confirm you’re metal-free before starting.

What if you forgot something?

Tell the technician before the scan starts. We’d rather pause for 30 seconds and remove a forgotten necklace than scan around it. Most studios have spare clean shorts and tops if you arrived in jeans by mistake.

Why this matters more for repeat clients

If this is your one and only scan, a small artifact won’t change the conclusion. If you’re tracking quarterly across a year, every artifact is a confounder. Rule of thumb: wear the same outfit (or as close as practical) every time. Same bra style, same shorts, same hair situation. Your dashboard charts will be cleaner.

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