Those embarrassing underarm stains come from your deodorant, not from your sweat," says Cobb. "If you really want to get rid of the stains for good, consider using a natural crystal deodorant which you can also get at the drugstore," she says. "You'll never have stains again!" If you prefer to keep your own deodorant, try one of these to get stains out:
1. When you come home from the gym or from exercising, take off your shirt and rub some Fels Naptha Soap into the underarms, then toss in the laundry and wash as usual. The soap will remove the deodorant residue and prevent staining, she says.
2. Try Cobb's "Miracle Cleaner". Like with wine stains, combine 1 part Dawn Original or Dawn Ultra
dishwashing soap with 2 parts hydrogen peroxide 3% solution. (Note that
you must use either of these kinds of Dawn because they are
concentrated, says Cobb. Other dishwashing products won't work as
well.) Pour the solution over the stain and work in with your thumbs. Launder as usual.