Guide
Why do shirts smell in the armpits after washing?
Because the wash doesn’t always remove what’s in the fabric. Odor compounds, bacteria and body oils can stay in a shirt’s fibers through a wash, especially in polyester and in cool water.
Try nuud: stop the smell at the source. One pea-sized dab, up to 72 hours fresh.
Shop nuudThe short version
The shirt smelled fine in the drawer
You take a clean shirt out of the drawer and it passes the sniff test. An hour into a warm morning, it smells the way it did before it went in the wash.
That isn’t your imagination. Sweat itself barely smells. The smell comes from bacteria breaking it down, and some of what they make settles into fabric.
Why it happens
Four reasons the smell survives the wash
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Polyester holds on to odor
A University of Alberta study found odor compounds are more attracted to polyester than to cotton, and a wash removes them less well from polyester.
How to tellThe smell comes back fast in sports tops and synthetic shirts.
What to doWear cotton for the shirts you sweat in most, and wash synthetics as soon as you can.
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It builds up
Each wear adds more odor compounds to the fibers. In the same study, five to ten washes made no significant difference to the amount left.
How to tellYour oldest running top fails the sniff test first.
What to doWash after each wear, not after a week.
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Cool washes leave more behind
Reviews of laundry research say that 50 C (122 F) and above is enough to reduce bacteria, and that leftover body fats are a likely food source for smell, especially at low temperatures.
How to tellEco or cold cycles, and the smell returns when you warm up.
What to doWash as warm as the care label allows.
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Wet laundry left sitting
Pseudomonas bacteria have been found on laundry left in the machine overnight.
How to tellA sour smell on a load that sat in the drum.
What to doTake clothes out when the cycle ends and dry them.
Meet nuud
Solo (Deodorant Cream)
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A deodorant cream that stops the smell, not the sweat. Gentle on skin, up to 72 hours fresh.
Shop nuudThe yellow stains
Antiperspirant is its own problem
Yellow marks in the underarm of a white shirt are a different problem from smell. A textile study found that antiperspirants with aluminum compounds form a gel-like structure with very poor solubility in water. On fabric it leaves yellowish stains that are very hard to remove in a regular machine wash.
In that study, pretreating with a stain remover that contains bleach improved removal. Check the care label before you use bleach on any garment.
Getting the smell out
How to get armpit smell out of shirts
Wash soon after wearing, as warm as the care label allows, and take the load out of the machine when it finishes. Pretreat the underarms if you see yellow marks. For the shirts you sweat in most, cotton lets go of odor more easily than polyester.
The other half of the fix is what’s under the shirt. If you stop the bacteria on your skin, less of the smell reaches the fabric in the first place. Our guide to how to get rid of armpit odor has the steps.
How nuud works
Start where the smell starts
nuud stops the bacteria that make the smell, with tiny bits of silver, and zinc oxide works on the sweat so it doesn’t turn smelly. There’s no aluminum in it, so no yellow antiperspirant marks. One pea-size dab per armpit works for up to 72 hours. Read more about the cream deodorant.
Start clean and dry
Apply after a shower, on dry skin.
Take a pea-size dab
That’s enough for one armpit. More doesn’t work better.
Rub it in
Rub it in until you can’t see it.
Questions
Shirt smell questions
Does polyester make you smell?
Polyester doesn’t create body odor, but it holds on to it. A University of Alberta study found odor compounds are more attracted to polyester than to cotton, and that washing removes them less well from polyester.
Can you get yellow armpit stains out?
Sometimes. Yellow marks from aluminum antiperspirants are very hard to remove in a regular wash. In a textile study, pretreating with a bleach-containing stain remover improved removal. Check the care label first.
What temperature should I wash workout clothes at?
As warm as the care label allows. Laundry research reviews say that 50 C (122 F) and above gives enough bacterial reduction, but many home cycles don’t reach it, so a warm wash and prompt drying matter too.
Ready to stop the smell?
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