Removing underarm stains from shirts can seem like an impossible task, especially when dealing with old or stubborn marks.
These unsightly yellowish or grayish shadows, often visible on white or light-colored shirts, are caused by the combination of sweat and deodorant residue.
Fortunately, there are several effective solutions to eliminate the problem using products you probably already have at home and by adopting a few simple precautions.
Why underarm stains form
Before understanding how to remove stains, it’s helpful to understand why they form.
Sweat itself is colorless and odorless, but when it comes into contact with aluminum salts found in many deodorants and antiperspirants, it can cause a chemical reaction that results in yellow or dark stains.
These stains become embedded in fabrics, especially in natural materials like cotton, making them difficult to remove with a regular machine wash.
Clean promptly
The first useful tip is to act as soon as possible if you notice fresh stains, rinsing the shirt under cold water before putting it in the laundry basket.
Hot water can set the stains, so it’s best to avoid it in the initial phase.
Also, don’t leave sweaty clothes in the basket for too many days: moisture promotes bacterial growth and makes the stain harder to remove.
Natural remedies to remove stains
Many natural products can help remove stains effectively, affordably, and without damaging the fabric.
Among the most effective methods are:
Baking soda: make a paste by mixing 3 tablespoons of baking soda with 2 tablespoons of water and apply it directly to the affected area. Let it sit for at least 30 minutes, then gently scrub and rinse. It’s ideal for white or durable colored shirts.
White vinegar: useful for dissolving deodorant residues and neutralizing odors. Pour the vinegar directly onto the stain, let it sit for 30 minutes, then wash the garment as usual. Vinegar is also suitable for more delicate fabrics.
Lemon juice: has a natural whitening effect and should be used mainly on white fabrics. Squeeze the juice onto a cloth, dab the stain, and let it dry in the sun before washing. Sun exposure enhances the lemon’s effect.
Hydrogen peroxide (3% solution): great for white shirts. Mix one part hydrogen peroxide with one part baking soda and one part water. Apply the mixture to the stained area, let it sit for 1 hour, then wash normally. Caution: do not use on dark or colored fabrics as it may cause fading.
Specific products for sweat stains
If natural remedies are not enough, there are specific stain removers available on the market for sweat stains, found in supermarkets and online.
Some of these are formulated to break down the proteins and salts present in sweat without damaging the fabric fibers.
If you choose to use one of these stain removers, always remember to read the labels and test it on a hidden part of the garment first.
Stubborn stains
For older or dry stains that don’t come out with the above methods, it may help to soak the garment for a few hours in a mixture of hot water, baking soda, and white vinegar.
Alternatively, you can pre-treat the area with a degreasing dish detergent (such as classic dish soap) applied with a soft-bristled brush.
Be careful not to scrub too hard, especially on delicate fabrics like linen or silk, to avoid damaging the fibers.
Be careful with delicate fabrics
Not all stain removal remedies are suitable for every type of fabric.
Shirts made of silk, viscose, wool, or other delicate materials require much gentler treatments than cotton.
For example, lemon and baking soda may be too harsh and cause fading or weaken the fibers.
In these cases, it's better to opt for specific detergents for delicate garments or, if the shirt is particularly valuable, take it to a professional cleaner.
Before trying any home remedy, always check the garment’s label to know what fabric you're dealing with and whether it tolerates water, rubbing, or acidic substances.
Don’t use the dryer on shirts with stains
A very common mistake is putting the shirt in the dryer before completely removing the underarm stains.
The intense heat of the dryer can set the stain permanently into the fibers, making it much harder to eliminate later.
For this reason, it’s essential to always check that the stain is completely gone after washing.
If not, it’s best to repeat the stain treatment and let the shirt air-dry, away from direct sunlight, which could also unevenly alter the fabric’s color.
How to wash shirts to prevent stains
In addition to removal, it’s important to adopt good washing practices to prevent stains from forming in the first place.
Always wash shirts after each use, even if they seem clean; invisible sweat can still settle into the fabric.
Use a mild detergent and avoid using too much fabric softener, which can leave residues.
For white garments, occasionally add a tablespoon of baking soda to the wash to keep the fabric bright.
Choosing the right deodorant
A great preventive strategy is to choose a deodorant free of aluminum salts, which are the main culprits in the chemical reactions that cause stains.
There are natural alternatives, such as deodorants made with baking soda, potassium alum, or cornstarch.
Choosing a more natural deodorant not only protects your shirts but also your skin’s health.
Removing underarm stains from shirts is not just a matter of aesthetics but also of hygiene and garment longevity.
Acting quickly, using the right remedies, and taking preventive measures can really make a difference.
Opting for natural deodorants, regular washes, and targeted treatments when needed will allow you to preserve your favorite shirts longer, free from unsightly stains or unpleasant odors.
Taking care of your clothes in a mindful way is also a sustainable choice that reduces waste and makes the most of what you already own.