Yellowed white T-shirts and sweat stains are a thing of the past; add a tablet from your medicine cabinet to your laundry

If you have a white T-shirt, you probably know this: sweat stains are almost unavoidable. You wear it just one time, and it's already going into the laundry basket. Then later you pull it out with a slight yellow ring under the arms that just won’t come out. Turns out, there’s a laundry hack that’s been quietly making the rounds online for years: dissolve aspirin tablets in water and soak your clothes in it. McGill University's Office for Science and Society says the trick is so popular that people have debated whether it really works or if it is just laundry room folklore.

Here is what is really going on, why those yellow marks show up, and whether that bottle in your medicine cabinet deserves a spot next to your detergent.

Why your white shirts turn yellow in the first place
Sweat itself is fairly colorless. The yellow color shows up because of a reaction, not because sweat is dirty. According to the Dry Cleaning and Laundry Institute International, perspiration contains salts, amino acids, and other compounds that oxidize when exposed to heat, such as an iron or dryer, and that oxidation is what turns fabric yellow over time. Most antiperspirants also contain aluminum-based compounds, and when those combine with sweat and body oils, they leave a residue that sticks to fabric fibers, which is why stains are usually found right under the arms.


So it’s not really a regular old “sweat stain.” It’s a slow chemical process, which is also the reason why normal detergent alone is often not enough once it has set in.

So does the aspirin trick actually work?
The logic of the hack is that aspirin has acetylsalicylic acid, which decomposes into salicylic acid when dissolved in water. Some people believe that salicylic acid, a mild acid, works to loosen the compounds that cause the yellowing.

But the science isn’t as cut and dried as social media would have you believe. According to McGill's Office for Science and Society, when researchers pitted salicylic acid’s reducing power against that of household bleach, aspirin was found to be well behind, and unlikely to make a shirt dazzle with bleach-like whiteness. Bleach is a powerful oxidizing agent, and aspirin is just not in the same league.

But that does not make the hack pointless. Whether or not it's aspirin, letting a stain soak in warm water for a long time, which is exactly what this method is, can itself loosen up dried-in residue. So people may swear by this trick because of the soak, not necessarily because of the tablets themselves.

The honest way to try it
Here's a simple version people often use if you want to give it a try. Crush 3 to 5 uncoated aspirin tablets and dissolve in a cup of warm water. Apply the paste directly onto the stain or soak the whole garment if the marks have spread; leave to sit for a couple of hours, then wash as usual.

It’s a simple, low-risk experiment. Aspirin is inexpensive; it won’t damage most common fabrics the way harsher chemicals can, and there is no clear evidence it will make a stain worse. If the person doing the laundry is allergic to aspirin, just skip it, and always test a hidden patch of fabric first.

What actually works, according to the experts
The American Cleaning Institute recommends a method with a little more solid backing: pretreat protein-based stains (technically what sweat residue is) with a detergent containing enzymes, then let the garment soak for at least 30 minutes, or longer for older stains, before washing. Aspirin was never designed to remove this kind of stain. Enzymes are created to attack biological residue like sweat and body oils.

Prevention is as important as removal. Allowing the antiperspirant to dry completely before dressing and washing sweaty clothes soon rather than allowing them to sit will help prevent yellowing before it starts. Some people also sprinkle a light dusting of absorbent powder under the arms before dressing so sweat won't soak directly into fabric. Corn flour powder is generally safer than talcum powder because some talc products have been linked to health issues and lawsuits in the United States over potential links to cancer, so corn flour is the more common recommendation today.

The bottom line
The aspirin trick isn’t a miracle cure, and it won’t be replacing your laundry detergent any time soon. But it’s a low-cost, harmless step that may help loosen up a stubborn stain, especially when combined with a proper soak and a good enzyme-based detergent. Think of it not as a secret weapon, but as a little helping hand. Still, the best way to keep those white tees white is to act quickly, use the right product, and not overthink your laundry routine.