What Causes Armpit Stains? (And What to Do About Them!)

What Causes Armpit Stains

You might assume that those yellow stains you’re seeing under the arms of your white clothing are from sweat – and you’d be halfway right. The yellow stains are actually caused when the minerals (like salt) in sweat mix with the ingredients in antiperspirant or deodorant (mostly aluminum.) This reaction causes a discoloration in the armpit area of light-colored clothing. 

Since everyone sweats, and you don’t plan on not wearing deodorant any time soon, it may seem like all of your white clothes are doomed to be stained, right?

Not so. You can actually get stubborn sweat stains out with household solutions or ordinary laundry products.

Stain-Removing Supplies

There are a few different treatment options you can try with items you probably already have. This includes:

  • Baking soda
  • Hydrogen peroxide
  • White vinegar
  • Enzyme-based stain remover 
  • Sponge, toothbrush, or other small brush

Treatment Option One: Baking Soda, Hydrogen Peroxide, and Water 

The most effective treatment option for sweat stains typically includes a mixture of equal parts baking soda, hydrogen peroxide, and water. You’ll rub that mixture on the stain using your sponge or old toothbrush. Then you can let the stained item sit for up to 30 minutes.

Alternatively, you can try white vinegar, and follow the same instructions. 

After the stain has sat, you’ll rinse it with cold water. Do not use hot water as that can set the stain and make it harder (or impossible) to get out.

Then you’ll wash it as usual. Check for stains once it has finished washing. It is a good idea to let it air dry a bit before you determine whether or not the stain still exists. Some stains will only show up if the garment is dry. If you still notice stains, you’ll want to try treating the stain again with a different option before you put the item in the dryer. 

Treatment Option Two: Stain Remover

If the first option didn’t work, you may be fighting a stain that has already set in and won’t come out. You can try an enzyme-based stain remover to see if it will work to get the stain out. You’ll apply the stain remover to the stain, let it sit for five minutes, and then wash it as usual. Double-check the directions for your stain remover, as they may vary slightly, but this is worth a shot if you are still struggling with a stubborn stain. 

Preventing Sweat Stains

While you likely aren’t going to stop wearing deodorant (please, don’t) – and you can’t control how much you sweat, you might use less of the deodorant you already use, especially if you think you might be using more than you need. You might also consider trying a different deodorant, which can help prevent yellow sweat stains from forming. For example, there are some aluminum-free deodorants you could consider, which might help cut down on the stains you’re seeing in your lightly colored clothing since there is no aluminum to react with the sodium in your sweat.