Every white T-shirt has a life story. Chapter one: crisp and bright. Chapter four: mysterious yellow underarms.

Quick answer: yellow pit stains usually come from sweat mixing with antiperspirant and body oils. Soak, pretreat, wash with enzymes and avoid the dryer until they're gone.

What causes them

Sweat on its own is mostly water. The yellow often shows up when sweat proteins and body oils mix with ingredients in some antiperspirants and build up over time.^†

So it's not you. It's chemistry with a grudge.

The fix

1. Soak the shirt in cool water with a dissolved sheet for an hour.
2. Gently scrub the underarms with a soft brush.
3. Wash with Just 9, whose enzymes target protein buildup.
4. Air-dry and check. Repeat if needed.

Prevent them

• Let deodorant dry before you get dressed.
• Wash shirts sooner, not after the third wear.
• Turn shirts inside out in the wash.
• Skip high heat in the dryer for whites.

FAQ

Why do my white shirts get yellow armpits? Usually sweat, oils and antiperspirant building up together.

Can yellow pit stains be removed? Often, with a soak and an enzyme wash. Old stains may take a few rounds.

Does the dryer make pit stains worse? Heat can set them, so air-dry until they're gone.

Which Just sheet for pit stains? Just 9.