Many women wear underwire bras but might be concerned that if they wear one when traveling by air that the wire in the bra may set off the airport security metal detectors.
This could potentially be embarrassing for them. So will that happen?
The Quick Answer: Will a bra set off a metal detector? TSA rules do not mention underwire bras specifically so they can certainly be worn through the security checkpoint. There is a very small possibility that they may trigger an alarm at the metal detector.
In general, most women’s experience of wearing an underwire bra through airport metal detectors at the security checkpoint is that they will not set off the alarm. My wife has certainly never had a problem.
There have been a few exceptions so if you are concerned then consider buying a wireless bra with plastic rather for support or a sports bra to wear when flying.
As well as bras containing metal these days many people, both men and women, often have metal body jewelry through their piercings so they also wonder about setting off the alarms at the airport. I will go into that aspect further on.

Contents
Will an underwire bra set off airport metal detectors?
Although it doesn’t happen very frequently, it is possible for an underwire bra to set off metal detectors when you pass through the airport security check.
On even rarer occasions it is possible for the metal hooks of a bra to set the alarm off during security checks but the machine would have to be very sensitive for this to happen.
If you happen to set off an alarm, and you believe it can only be due to you having wire in your bra, then tell a female security officer.
She will probably use a handheld metal detector wand initially to see where you set off the metal detector. She may then want to do a manual “frisk” and you would be well within our rights to ask for this to be carried out in a private area. You will not be asked to undress.
You could also be asked to pass through a full body scanner.
What to do if you are worried
The easiest thing to do if you are worried about wearing a bra that has wire as support would be to not wear one. Instead consider wearing wireless bras with plastic support or even a sports bra.
You will have no problems wearing a wire-free bra so you will be worry-free.
TSA rules and underwire bras
There is only one reference I can find on the TSA website (tsa.gov) relating to whether you can wear an underwire bra through airport security and what might happen if you set off an alarm.
In a weekly review post about airport security it states, with a very poor pun:
“A box cutter was discovered in a passenger’s bra after alarming the AIT machine at Nashville International Airport on August 7. Why!? An underwire should be the only metal item in your bra. Attempting to conceal items can lead to bra-blems, including a civil penalty and possibly being arrested.”
I managed to find a few references to underwire bra airport security scans on the TSA Twitter service. The @AskTSA service is very good as you can ask a specific question about what you can take through airport security and they will give a very prompt answer.
The first I found was someone asking about wearing undergarments with underwires. The TSA response was that if the alarm was set off then additional screening would be required which may include a pat down.

The second tweet was referring to a personal security screen by someone who was panicking about what they had been told to expect and the TSA’s reply giving details of what can be expected:

This is a news item about do underwire bras go off on metal detectors at airport security:
Can I bring underwire bras in my carry?
You can pack as many underwire bras as you like in your carry on bags without any problems.
This is confirmed by the TSA on Twitter when a passenger asked about taking bras with wires with them:

Can airport scanners see through clothes?

When you stand in one of the latest airport security AIT scanners the operator will not see a picture of you naked if that is what is worrying you. The operator actually sees a representation of a body with the position of any items of interest marked.
Airport body scanners can detect both metallic and non-metallic items on a person’s body that might not otherwise be detected by the more common metal detectors. The body scanners can detect items around the body but can’t actually see inside the body.
Do nipple piercings set off airport metal detectors?
Particularly as most body jewelry is made of non-ferrous (non-magnetic) it is unlikely to set off the alarms at the airport.
If it does then as you will see below you may be subject to a manual check or even be asked to remove your nipple piercings or other body piercings (in private of course).
The TSA does state on their website:
“Certain metal body piercings may cause the machines to alarm and a pat-down may be required. If additional screening is required, you may be asked to remove your body piercing in private as an alternative to the pat-down.”
https://www.tsa.gov/travel/frequently-asked-questions/should-i-remove-my-body-piercing
A reply from @AskTSA on Twitter regarding nipple piercings:

If you have any metal surgical implants you may wish to read my article about passing through airport security with metal implants
FAQs
Do you have to take piercings out at airport security?
If you set off the alarm and you believe it is because of your piercings then you may be asked to remove them by a security agent. If they are in an intimate area then you will of course be allowed to do this in private.
Do piercings set off metal detectors?
It is possible for certain metal body piercings to cause the security machines to alarm when you pass through. If this happens then a pat-down may be required and along with additional screening. You could be asked to remove your body piercings in private as an alternative to the pat-down.
Will a nose piercing set off the alarm at airport security?
It is extremely unlikely that a nose piercing will set off the alarms. If it does then you may be asked to remove it and pass through the machine again.

I have been traveling around the world by air since the early 70s and living overseas too. I worked for British Airways for a number of years and I am also a private pilot. About Me