What Causes Black Underarm Stains and How to Prevent Them

Dear Home Ec 101,
I have black underarm stains on many of my shirts. That’s right – BLACK. It started happening after we moved to the mountains of western NC where we have well water, but it’s only my shirts – not my husband’s. I’ve tried changing deoderant (though I suspect they all have the same active ingredients) with no effect. I’ve tried scrubbing the stains with various stain removers. Nothing. The stains are on the inside of the shirts – but after a while it shows through to the outside of any light-colored shirts. I’ve never seen anything like it before and – to be honest – it makes me feel like kind of a freak. Can you help?
Funky in Franklin

Heather says:

Antiperspirants and deodorants are two distinct products, but in our everyday speech we tend to use the terms interchangeably and I have done so throughout this response as a way to help people using search find what they need.

How to Prevent Black Underarm Stains

You were on the right track when you tried switching deodorants. If you take a walk down the antiperspirant / deodorant aisle, you’ll notice quite the selection. Most of the antiperspirants / deodorants you see will all have the same active ingredient(s): aluminium chloride, aluminium chlorohydrate, aluminium-zirconium or a combination of thereof. Did you notice something about those three active ingredients? They all contain aluminum.

For most of us the aluminum in antiperspirants isn’t a big deal, it helps us stop sweating from our underarms for a few hours and we go through the day without offending our neighbors. Neat.

However everyone’s body chemistry is a little different, it’s the food you eat, the water you drink, and your genetics. You know how everyone likes to giggle about what eating asparagus does to urine? Well it doesn’t do that to everyone’s. Some people think cilantro tastes like soap -and I cry a little for all they miss. Your quirk is that something in your sweat, is making that aluminum show up on your shirts, lucky you.

Since we’re all special snowflakes the first tip is specific to people, like you, who have dark stains from their deodorant / antiperspirant.

Avoid the aluminum

Try switching to an aluminum free antiperspirants / deodorants I did a search on Amazon that will show you specific brands and labels to look for the next time you head to the store.

On a side note, some people avoid aluminum because they believe that aluminum is the cause of of Alzeheimer’s. That hasn’t been proven, what they’ve found is that people with Alzheimer’s tend to have more aluminum in their brains, this doesn’t mean that the the aluminum was the cause, it just means that it shows up in people’s brains when they have Alzheimer’s. It could be like the way ketones show up in the urine of diabetics, the insulin is absent so ketones show up where they normally wouldn’t. Just because something is there, doesn’t mean it is the cause. (I haven’t done a lot of research lately, but feel free to link to peer reviewed sources, if you want to discuss this point).

You didn’t mention where you moved from. Why do I ask? Well, if you moved from a cooler climate, there is a chance part of the problem is that you haven’t had to use as much antiperspirant as you do now.

Use less antiperspirant.

Antiperspirant works by blocking your pores -I’m simplifying here- once those pores are blocked an extra coat of the white stuff isn’t going to be helpful, it’s just going to rub off on the inside of your clothing. When your antiperspirant wears off and you begin sweat, you’ll have more aluminum hanging out on your shirt to react with your sweat and create that dark stain.

For those of us that don’t react to aluminum, this means we have to remove deodorant build up from our shirts.  You can try to remove the dark stains with the same tips as in that article, but with the chemical change, it may be permanent.

Additionally, try to let your antiperspirant or deodorant dry completely before putting on your shirt. This will also help reduce the amount absorbed by the fibers of your clothing.

So your homework is to find an aluminum free antiperspirant / deodorant, use less, and try to let it dry before putting on your shirt to prevent future stains.

Got it?

Submit your questions to helpme@home-ec101.com.


  1. Kim says

    I had the same problem with a couple of white shirts. After washing (but before drying) I placed the shirts into a small dishpan with oxi clean added. I let them soak several days and the stains became much lighter.

  2. MaggieM says

    I don't get dark stains but I do have trouble with yellow pit stains (and it's way worse on my right underarm, isn't that weird?). It was incredibly frustrating/annoying until I learned about the powers of vinegar. Now I keep a spray bottle of straight-up, household strength, white vinegar next to my stain spray at the washing machine. ALL of my shirts, but especially light colored and white ones, get a spray of vinegar on the pits before washing. It has made a world of difference. Oxy clean (and the like) works great, too.

  3. Jess says

    Point of info if you are switching to non-aluminum (which some do for breast cancer fears as well). It takes about 2 weeks for your body chemistry to adjust to the new deod/antip. But once it does, the non alum ones will work as well as the old ones, except in heavy (running/biking or hot summer situations). I recommend for those two weeks carrying the deodorant with you as well as wipes – baby wipes, handwipes – and wipe clean and reapply whenever needed.

    • Lyndsi says

      most crystal deodorants still have Aluminum in them!! You have to be very careful! Read all of your ingredient labels!

  4. says

    I've had allergic reactions to several of the more mainstream anti-perspirants and have been using non-aluminum versions for years now (I don't know what the allergy is to, but these don't bother me the way the others do). One thing I have found is that different ones work better than others for different people so if one doesn't work after a few weeks try another one instead of just giving up. The one that seems to work best for most people I know who have a similar problem is the Crystal brand sticks (you can get them at Whole Foods, Amazon and probably other places as well and they last a really long time). The only thing is that the smoother your armpits are the better they work (a lot of guys have problems with them because of this). I only mention this because for a while I was wondering if my only choices were itching (due to the allergy) or being stinky as the summer highs were I live are generally 110-115. Hopefully this helps others who are trying to avoid aluminum deodorants, etc. for whatever reason.
    My recent post this moment

  5. Kate says

    I'm disappointed you didn't mention natural deodorants . . . like using baking soda or corn starch or apple cider vinegar. Any one of them is worth a try, especially for someone experiencing a bad reaction to a typical antiperspirant or deodorant. It's easy to find instructions and anecdotes on the web from others who've tried natural methods.

    Personally, the only deodorant I've ever had a bad reaction to at all was an all-natural brand: Tom's of Maine. It would sting and burn my underarms after each use. My husband on the other hand, cannot use products containing aluminum at all and most natural products on the market cause cause him rashes and peeling skin. We both use apple cider vinegar now, which doesn't keep us from sweating (but please remember, sweating is a natural body function . . . antiperspirants inhibit the natural cooling efforts of your body, which many people feel is very dangerous for your health), but does keep you from smelling.

  6. Amanda says

    I use only all natural deodorant, or none at all. Although I have never had black stains, the yellow stains have stopped since I made the switch.

  7. Bonnie says

    Just a note regarding those Crystal deodorants: the active ingredient is an aluminum salt, so I don't know that switching to it would help if aluminum is causing the black stains. I use an unscented roll-on deodorant from Home Health called Herbal Magic and found that it works better than any other deodorants I've tried. I think it may be the baking soda in the formula. I agree with the comment to try several until you find one that works for you.

  8. Lucy says

    Hmmm, I get black sweat stains on my bras, under the Girls, not under the arms. I'm sure not putting deo/anti-p there, and I use a non-aluminum one anyhow. My only solution, after many tries with various products, is to toss them when I can't stand them any longer. Any siggestions?

  9. Lisa Reynoso says

    Speaking of natural alternatives, my husband hit on a really good one recently. Get a bottle of tea tree oil from the pharmacy and rub a drop under each arm after bathing. In cooler weather, this will last me 2 days (if it's hot, I shower every day anyway). The idea is that it prevents bacteria growth, which is what is causing the smell in the first place. If you are wearing a tight-fitting top, you should put it on right away after applying the oil so that a little gets on the clothes, or you could get bacteria growing in them even though your skin doesn't smell.

    Of course, this doesn't prevent sweating, but unless you sweat excessively and it shows as wet spots, it's probably not really an issue.

    I've also heard you can do the same thing with grapefruit seed extract. I've never tried it, but since that kills bacteria, it should work. I think the tea tree oil is cheaper, though.

  10. Rebecca says

    Very interesting! I didn't know that some people had a hard time with dark sweat stains.

    And yeah, I'm one of those who thinks cilantro tastes like soap. Even just a little bit is enough to ruin a dish for me. 😛

  11. MANZIMAMA says

    This is great!  I always wondered why my shirts always get a dark stain under the arms. it is so annoying, it makes all my shirts look old and dirty when they are not.  I’m going to try aluminum free.  Thanks for the tip!!!  Is there any advice on getting out the stains after they have been dried and been there for a while?

  12. Ronomar says

    I have the same thing happening with my bras, and don’t know what to do.  Did you ever find out what was causing it or any remedies?

    • annette kendry says

      This may sound strange but my daughter’s friend only ever drank tequila when they went out with friends and she ruined all her tops due to black underarm stains on them. When she borrowed my daughter;s clothes at times they were always returned with these black stains. However when she stopped drinking tequila the problem went away.
      I removed the stains from the soiled tops she borrowed with dawn dish detergent and gylcerin (worked like a charm.

  13. Workedforme says

    Are you using pods detergent?  We started getting those black stains a few months ago, sometime after we started using pods.  We just switched back to regular powdered detergent and the stains went away within 1 or 2 washings.  I can’t blame the black stain on antiperspirants – we’ve used them for years and never had black stains before.  I originally put the pods in the soap dispenser and a few months later realized you are supposed to put them in the barrel of the washer.  Even so, the stains didn’t come out after changing where I put the soap.  But reverting to powdered Tide removed all the stains very nicely. 

  14. Donna says

    Will aluminum cause light stains on dark fabrics as well? I have dark stains on light-colored shirts, and light stains on dark-colored shirts. I haven’t tried the non-aluminum deodorant yet.

  15. Joy says

    I had/have the same problem. It went away after I had my son and now it’s back after I had my 2nd daughter. I’ve used the same deodorant since I first started using deodorant and I’m 32 so a little over 20 years. I add bleach to every wash and still the stains are getting darker and darker. Idk what to do anymore because this is ruining my clothes.

  16. Mary says

    As soon as I saw “aluminum,” I took my son’s light pink shirt with the black underarm stains and applied aluminum jelly to the underarms. Stains gone! I’ll also ask him to use a little less deodorant – he’s very hygienic. :)

  17. Jennifer says

    I am a healthy woman with very healthy sweat-glands(since I turned 12) and I have passed these on to my 14 yr old daughter. We both have to keep Antiperspirants handy for the hot days or else we can’t stand to smell ourselves. I noticed that our shirts were developing stiff black stains on the underarms after moving to the NC mountains. I think the cause may be a combination of our sweat chemistry, the aluminum ingredient our hygiene products, and the mineral content in the water used to clean the close. I have come to this conclusion since the stains don’t appear until after washing and drying them.

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