Skip to content
Ask Dr. Laundry

Ask Dr. Laundry

Eradicating Underarm Stains

By Dr. Laundry June 17, 2011

Q:   My husband and I recently purchased our first washer and dryer.  With them came some tips on stain removal; however the application instructions were vague.  My husband has some shirts that are stained in the armpit area, I believe due to the combination of his deodorant and perspiration.  The tip states to pre-treat with boiling water then equal parts baking soda, hydrogen peroxide & water; rinse and then detergent pre-soak.  How should I apply these items to the shirt (i.e. put the shirt in container with these items or simply pour them over the affected area on the shirt)? This is a new process for me and I am unsure how to apply this valuable tip. 

A:  How nice to have your own washer and dryer; now you will have more time without having to go to and from the launder mat!  It is also great you read the washer’s instruction guide.  I agree that the underarm stain removal tip sounds a little confusing.  These stains are hugely problematic, partly because they are highly variable.  On some t-shirts, it is a crusty buildup of deodorant; others can just have a light transfer of anti-perspirant, and unfortunately with garments like silk tops, it is permanent discoloration.  Light smears usually come off with regular washing.  For the crusty build up, it is better to not let it happen in the first place, so start fresh with your new washer by stocking up on white undershirts for your husband.  Then proceed as follows:


  1. Pre-treat the armpits of each white t-shirt with Clorox® Bleach Pen Gel:  use the broad scrubber tip to apply the gel and gently rub it into the stain.  Since you want to prevent build-up, do this every time you wash the shirts, whether or not you see a stain.

  2. Wash immediately in hot water with detergent and ¾ cup Clorox® Regular-Bleach.

  3. Tumble dry with the rest of your white load.


Ideally, the white undershirts will protect your husband’s other colored shirts from getting any underarm stains that cannot be easily bleached away.  But for a colored shirt, you can try pre-treating the armpits each time you wash the shirt (again, to prevent build up) as follows:

  1. Apply liquid Clorox2® Stain Fighter and Color Booster directly to the armpit area and rub in; wait 3-5 minutes (do not let it dry on the fabric).

  2. Wash immediately in the hottest water recommended on the care label with detergent and additional Clorox2® based on your load size.

  3. If there were obvious underarm stains that you pre-treated, then be sure to air dry the shirt and check for success; repeat if necessary.


If you would like to attempt using the washer’s user guide recommendation, try this method:

  1. Working in a dishpan, pour boiling water slowly through each armpit stain.  This is to “melt” the build-up, which is a combination of deodorant, sweat, body soil, bacteria, etc.  Before you start, it will be helpful to position the shirt in the dishpan so you will not have to touch it once you start since it will be boiling hot!

  2. Do not rinse the shirt – just pour off as much of the hot water as you can.  This keeps the build-up in a more “melted” state.  And if you do need to handle the shirt, either use kitchen tongs or wear gloves.

  3. Apply the mixture of 1:1:1 parts baking soda, hydrogen peroxide, and water directly to the stain.  Sometimes this is referred to as a paste, but it is actually quite watery, so be sure to blend the mixture enough to saturate the stains.

  4. Rinse the shirt, and then follow up with a hot water wash with a good enzyme-containing detergent.  (For white t-shirts, be sure to add ¾ cup Clorox® Regular-Bleach!)


For ongoing prevention of underarm stains, personally I think this last method is way too much work, and I would start fresh with new t-shirts and stick with the previous treatments. 

Have any of you experienced similar stubborn stains?