Gel deodorants often are less likely to leave stains on clothing because of their transparent color, as opposed to the white color of most roll-on and stick deodorants. Even gel deodorants, however, can leave underarm stains over time if they contain the antiperspirant ingredient of aluminum salts. These salts can react with perspiration, which can cause discolored areas to appear in your clothing over a period of extended use. Luckily, you can remove these stains fairly easily using inexpensive products.
Crush two aspirin and place them in 1/2 cup of hot water.
Pour the solution water containing the dissolved aspirin onto the stained area and allow it to sit for two to three hours.
Add 1 cup of white vinegar to your washing machine.
Place the stained clothing in the washer and launder it as you normally would.