A woman's disposable period underwear was enough to get her pulled aside at airport security for a pat-down, front and back, over what turned out to be nothing more than trapped moisture. She had walked through the scanner like everyone else, only to be shown an image flagging her crotch as an area of concern.
The TSA agent explained that pads can set off the machine because of the extra material, and that reusable period underwear can trigger it too, thanks to moisture held against the body. The traveller shared her experience on Reddit, and it quickly became clear she was far from alone.
Why Moisture Sets the Machine Off
Period underwear traps fluid by design. A waterproof polyurethane barrier sits beneath dense, absorbent layers that hold liquid close to the skin, and a millimetre-wave scanner reads that density the same way it reads anything else flat and concealed against the body, as a potential threat.
The scanner operates by classifying each traveller before they even step in. A TSA officer presses a button marking them as male or female based on presentation, and the machine then compares the resulting image to a standard template based on that classification.
Any deviation gets flagged, whether that is a pad, a chest binder, or the layered, liquid-retaining fabric in period underwear. It is the same underlying issue that has seen the technology repeatedly misread natural Black hairstyles and transgender bodies as anomalies too, so this is a known blind spot rather than an isolated incident.
Got flagged at TSA and the woman there refused to pat me down so I was just stood there like🧍♀️ until they found someone who was comfortable patting down a trans person 🙃
— tori (@bluerosetori) September 4, 2025
a line formed and i wanted to cry
The Workaround Women are Sharing
Commenters on the original thread shared a tip they learned directly from a female TSA officer. The advice was to stand slightly wider than the footprint markings and to squat slightly, which helps ensure that nothing appears squished together on the scan. One traveller noted that this was the first time she was able to go through security while wearing period underwear without setting off an alarm.
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by u/NoBusForYou from discussion
in TwoXChromosomes
Some individuals were not as fortunate. One person was flagged due to a folded tissue in their pocket, while another felt that the machine had mistakenly identified her own anatomy as suspicious. This also raises a quiet anxiety for many travellers: would a menstrual cup set off the same alarm? Unlike pads or period underwear, a cup without a protruding stem is entirely internal and unlikely to be detected.
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by u/NoBusForYou from discussion
in TwoXChromosomes
Know Your Rights if You're Flagged
If a pat-down is necessary, the TSA's guidelines clearly outline specific limitations. Officers are required to use the backs of their hands on sensitive areas, reserving the use of their palms for rare instances when a threat cannot be ruled out. Additionally, the search must be conducted by an officer of the same gender as the individual being searched.
Travellers can request a private screening room with a witness of their choice at any time, or they can ask for a supervisor if anything feels inappropriate. Complaints can also be submitted afterwards through the TSA's website, which the agency states helps in tracking patterns at individual checkpoints.
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by u/NoBusForYou from discussion
in TwoXChromosomes
None of this should fall on travellers to manage alone. Wearing fresh, dry products or learning the stance might reduce the odds of being stopped, but they are workarounds for scanners that were never built with ordinary female biology in mind.
