Armpit sweat may not be the nicest topic to talk about, but it’s something that affects us all and something that you may find is a problem from time to time.

First of all, let’s clear something up—sweating is totally normal! It’s how we regulate our body temperature and it’s what keeps us cool when we’re feeling too hot.

On this page we take a closer look at armpit sweat including:

Why do armpits sweat?

The human body has around 2–5 million sweat glands. Some people have more than others and therefore produce more sweat. Armpits are one of the more noticeable areas where we sweat, because there’s a higher concentration of sweat glands in this area, particularly apocrine sweat glands.

The apocrine sweat glands produce sweat that has more protein and carbohydrates in it than eccrine sweat glands (the other type of sweat glands that are found all over the body).

Apocrine sweat is thicker than eccrine sweat (which is mainly water) and, as unpleasant as it sounds, apocrine sweat tastes really good to the bacteria that live under your arms.

A surge in adrenaline causes the apocrine glands to produce sweat1, which means we tend to produce more underarm sweat in stressful situations—the last thing you need in a high-pressure meeting! This also means you sweat more during a workout too, as your body produces adrenaline as it works harder2.

To add to this already not very pleasant situation, apocrine sweat is also partly responsible for the yellow sweat stains you might find in the armpit area of some of your tops and dresses. The other culprit for these yellow stains is the reaction between the aluminium chlorohydrate, an ingredient in some anti-perspirants, and your sweat3.

The science behind sweating is all well and good, but if you’re at work (or anywhere!) and notice sweat patches under your arms, it’s hard to not feel a little self-conscious.

How can I prevent armpit sweat stains?

Those unattractive yellow armpit stains are caused by the reaction between some of the chemicals in anti-perspirants and your sweat.

There are a few simple things you can try that should reduce the risk of getting yellow stains under your arms:

  1. Wear natural fibres and choose loose-fitting styles if you can—think lovely floaty linen, cosy wool or soft cotton.
  2. Apply anti-perspirant to clean dry skin and let it dry before you get dressed.
  3. Don’t apply too much anti-perspirant—this can cause product build-up which can actually make the stains look worse and lead to lingering armpit smells.
  4. Pop your clothes in the wash as soon as you take them off, as odours and stains can be worse if they’re left in your washing basket.

You can read more about anti-perspirant stains and find out how to remove them here.

Is roll-on, spray or stick anti-perspirant most likely to cause stains?

No product is worse than the other at creating armpit stains, but if you don’t let your anti-perspirant dry properly before getting dressed then this could increase the chance of stains.

Roll-on and stick anti-perspirants take a little longer to dry than spray products, so if you’re regularly rushing out of the door in the morning, switch your roll-on or stick for spray anti-perspirant, which dries instantly.

Does deodorant cause stains?

Even though most deodorants don’t include aluminium (the main stain-causing ingredient in anti-perspirant), if you apply too much deodorant, you may find the product builds up over time and causes stains.

How can I get rid of armpit stains?

One popular tip is to try applying white vinegar to the stains or if one of your tops has a dried yellow stain on it then try the following:

  • Make a paste of three parts baking soda and one part water.
  • Gently rub this onto the stain.
  • Leave it to soak in for a couple of hours before popping into the washing machine.

But don’t forget—always try a patch test before applying any type of stain remover to your clothes!

And for tips on how to deal with stains on delicate materials like silk, read our guide How to remove anti-perspirant stains from clothes.

using washing machine

Why do some of my clothes have an unpleasant underarm smell even after washing them?

If you find your clothes still smell under the armpits after washing them, this could be because product has built up on the fibres.

Product build-up could be caused by deodorant, anti-perspirant, washing detergent or fabric softener, and over time this traps odour-causing bacteria. This can often be more noticeable in sweat-wicking materials, such as cotton, or clothes that are stretchy and have more fibres4.

How can I get rid of unpleasant armpit smells on clothes?

As with stains, using baking soda should help to banish unpleasant smells. Add half a cup of baking soda to your wash load to help your detergent work more effectively.

If the smell is particularly strong then try the following:

  • Pop your top or dress in a solution of one part vinegar and four parts water.
  • Leave to soak for 30 minutes.
  • Wash the garment in the washing machine as you normally would.

Make sure you check the care instructions for your clothes before trying the above and definitely don’t try this on delicate fabrics such as silk!

To find out more about how anti-perspirant works and how it helps to prevent sweating, visit our anti-perspirant advice centre.