The Science Behind Armpit Stains & How to Stop Them

The Science Behind Armpit Stains & How to Stop Them

We know the feeling. Your go-to reliable shirt starts to show underarm stains that are hard to remove. Especially on your best white shirt. There is a simple explanation as to why yellow sweat stains start to appear.

It is caused by the interaction between sweat and particular active ingredients used in most standard deodorants.

Sweat itself is not the main culprit behind armpit stains. It is mostly composed of water and electrolytes, such as sodium and chloride. However, sweat can also contain trace amounts of other compounds, including urea and ammonia, which can react with substances in antiperspirants to cause discolouration.

Antiperspirants typically contain aluminium-based compounds, such as aluminium chloride or aluminium zirconium, which help reduce sweat production by temporarily blocking the sweat glands. These compounds form a gel-like plug that inhibits sweat from reaching the skin's surface. However, when these compounds come into contact with sweat, a chemical reaction can occur, leading to the formation of yellowish stains on clothing.

To help prevent armpit stains and minimise their appearance, you can try the following tips:

Choose Antiperspirants Wisely:Opt for antiperspirants that have a lower concentration of aluminium-based compounds. Some antiperspirants also contain alternative ingredients, such as natural minerals or plant-based compounds, which may be less likely to cause staining.

A fantastic option is the BodyShop one here, containing simple ingredients.

Allow Antiperspirant to Dry:Ensure that you apply antiperspirant to clean, dry skin and give it enough time to dry completely before putting on clothing. This can help reduce the likelihood of the antiperspirant coming into contact with sweat and staining the fabric.

Use Sweat-Wicking Fabrics:Wear clothing made from breathable and moisture-wicking fabrics, such as organic cotton, linen and hemp. These fabrics help draw moisture away from the skin, reducing the amount of sweat that reaches the fabric and potentially causing stains.

Launder Clothing Properly:When washing clothing with armpit stains, we don't suggest using a stain remover or pre-treatment product as they tend to be bad for the environment. Consider the following alternatives to help. 

An easy at home remedy is to soak the garment in a solution made of part white vinegar and warm water. Then take some baking soda, salt and hydrogen peroxide to create a paste that can be applied to the area and let it soak for a couple of hours. Continue to wash as usual. Follow the instructions on the product and wash the garment in the appropriate water temperature recommended by the clothing manufacturer.

Also, consider how long you leave your garment to sit in your laundry basket. The longer you leave your stained garment, the harder it is to remove it.

For our London-based customers, you can also choose Blanc, an eco-friendly award-winning launderette that takes care of luxury garments without using harmful methods.  

It is always better to prevent stains from occurring, so change up your anti-perspirant routine and see the difference. Our shirts at Alder & Green are made of an organic 2-fold 100 yarn, meaning the shirts are the perfect mid-weight fabric in every season. This means that for all seasons it should be breathable in all seasons due to the natural fibres, causing less sweating overall. Take a look at the collection here.