Let's get straight to it — here's what actually matters on this one.

• Soak stained areas in a mix of baking soda and water before washing, rather than using harsh bleach directly on the fabric.
• White vinegar diluted in water is a gentler alternative that breaks down sweat residue without damaging fiber structure.
• Avoid high heat drying on stained areas until the stain is fully gone — heat can set sweat stains permanently into the fabric.
• For recurring underarm staining, an antiperspirant with aluminum-based compounds is often the actual cause — switching products can help alongside better washing.

The fit-and-fabric-health takeaway: Sweat stains build up in the same high-friction zones that already see the most skin-fabric contact — treating them gently protects both.

Next up: check out our guide on whether dry cleaning or machine washing is safer for suits.