Nothing makes a favorite white T-shirt look older faster than yellow underarm stains. And while most people assume sweat itself is to blame, those stubborn marks are actually the result of a chemical reaction happening over time in your laundry basket. The good news: The right detergent—an enzyme-based detergent—can help break down the sweat, body oils, and deodorant residue behind the discoloration and lingering odors.
“Enzymes help break down proteins, oils, and other organic soils that contribute to stains and lingering odors," says Noah Pinsonnault, a reviews analyst in the Good Housekeeping Institute Home Care & Cleaning Lab. For activewear or performance fabrics, a sports detergent can also help, since those materials tend to hold onto odor more stubbornly than cotton.
In other words, it’s not just about getting clothes “clean,” it’s about breaking down what’s left behind in the fibers after sweat dries. That's because sweat stains aren't just sweat stains. “It’s usually a combination of sweat, body oils, and deodorant residue," says Pinsonnault. "Sweat itself is generally colorless, but proteins, oils, and salts can react with deodorant over time, leading to yellowing.”
Once that buildup starts bonding with fabric, it doesn’t always come out in a normal wash cycle. And the longer it sits—especially through heat and repeated wear—the more it tends to set in and darken.
What to look for in a detergent
When it comes to sweat stains, the most important factor is less about fragrance or concentration and more about whether a detergent contains enzymes that target protein- and oil-based stains. These enzymes break down the compounds left behind after sweat dries, helping lift them from fabric fibers so they rinse away instead of building up over time. Without them, sweat, body oils, and deodorant residue are more likely to linger in the fabric, even after a full wash cycle.
In testing, Tide Original Liquid consistently ranks as a top performer. It contains multiple enzymes designed to tackle common laundry soils, including sweat-related buildup, and performs well across both high-efficiency and standard machines.
It also stands out for its effectiveness in cold water washes, where many detergents struggle. In our tests, it continued to break down grease- and protein-based stains even at lower temperatures, making it a reliable everyday option for everything from white T-shirts to workout clothes.
How to tackle sweat stains
Removing sweat stains isn’t just about what you wash with, it’s about how you treat the fabric before it ever goes into the machine.
- Start by pretreating the stained area directly. Work a small amount of liquid detergent or an enzyme-based stain remover into the fabric using your fingers or a soft brush. Let it sit according to manufacturer's instructions, so the enzymes have time to start breaking down buildup before washing.
- For older or more stubborn stains, soaking can make a noticeable difference. Submerge the garment in warm water mixed with a few tablespoons of detergent for 30 to 60 minutes before running a full wash cycle.
- Wash using the hottest water that’s safe for the fabric, according to the care label. Hot water helps loosen residue, but only when the fabric can handle it.
- Check the garment before drying. Heat can lock in any remaining discoloration, turning a treatable stain into a permanent one. Air-drying first gives you a chance to catch anything that needs a second round.
Brigitt is a writer, editor and craft stylist with nearly 15 years of experience. She specializes in lifestyle topics, including home, health, parenting, beauty, style, food, entertaining, travel and weddings. She has written for Glamour, People, Good Housekeeping, Women's Health, Real Simple, Martha Stewart, Apartment Therapy, The Spruce, and more.
