You Can’t Prevent Pit Stains—You Can Only (Temporarily) Disguise Them

Let’s get one thing straight: Sweat doesn’t cause those gross yellow stains on your nice white shirt. The culprit behind those jaundiced splotches is aluminum, the active ingredient in most antiperspirants — and some deodorants — that chemically reacts with the protein in sweat to cause underarm yellowing. (It’s this same...