Can you remove old yellow sweat stains?

Yes. The baking soda and peroxide method works on old stains but may need multiple applications.

How do you prevent sweat stains on shirts?

Use aluminum-free deodorant, let it dry before dressing, wear undershirts, and pre-treat armpit areas before washing.

Yes. Soak in OxiClean solution for 1-6 hours before washing. It's effective on both fresh and set sweat stains.

Yes. The vinegar soak method is safe for colors. Avoid hydrogen peroxide on dark colors as it can lighten them.

Stain Removal

Stain removal is all about speed and technique. Here's the proven method for tackling sweat stains effectively.

1
Make a stain-removal paste
Mix 2 tablespoons baking soda, 1 tablespoon hydrogen peroxide, and 1 tablespoon water into a paste.
2
Apply to the stain
Apply the paste to the yellow armpit stains. Work it into the fabric with a toothbrush. Let it sit for at least 30 minutes.
3
Soak in vinegar
For stubborn stains, soak the garment in a mixture of one part white vinegar to four parts warm water for an hour.
4
Wash on warm
Wash with Power Wash Laundry Detergent on the warmest setting safe for the fabric. Sun-dry white shirts for extra whitening.

TIPYellow sweat stains are caused by aluminum in antiperspirant reacting with sweat proteins -- not sweat alone.
TIPSwitch to aluminum-free deodorant to prevent future yellowing on your white shirts.
TIPPre-treat the armpit areas of white shirts before every wash, even if you don't see stains yet.

XUsing bleach on yellow sweat stains, which actually makes them more yellow due to a chemical reaction with the proteins.
XIroning over sweat stains before treating them, which permanently heat-sets the discoloration.
XUsing hot water before treating, which cooks the protein stain into the fabric.

Bleach reacts with the protein in sweat stains, intensifying the yellow color. Use hydrogen peroxide and baking soda instead.