20 Mar 2025
Let’s imagine you’ve just taken your favourite white tee shirt from the wash. All ready for you to look your best, but hang on… what are those odd-looking yellow underarm stains?
Two words: sweat stains.
Yes, you’ve just washed your top so there shouldn’t be anything there. But sweat stains are complicated.
why do some of us get sweat stains?
Because not everyone does… in fact most probably don’t but when they do occur they are frustrating at best and you’ll want to know how to tackle them.
And why are they yellow? Because surely sweat itself is clear?
The yellow colour comes from a heady cocktail of sweat, natural skin oils and bacteria having a wild party on your clothes. Toss in the aluminium salts that are found in all antiperspirants, and boom - yellow underarm stains.
It’s not to be confused with purely product stains which are white. These are the ones that show up when you’re rushing to get dressed and they’re purely product residue - mostly from antiperspirant particles that decided not to stay put on your skin.
So how do we beat the stains at their own game?
the quick fix.
If you notice white deodorant marks while dressing, grab a pair of nylon tights and gently rub the stain. It’s weirdly satisfying and works like magic.
the longer game.
If those stains are proving stubborn then smol stain gel should take care of them.
Wet the deodorant stain and apply smol stain gel directly to the white marks. Leave the gel in place for a couple of minutes before rinsing and washing your clothing as usual.
But what about those more colourful yellow underarms?
The secret to fighting antiperspirant and sweat stains is acids! They break down those stubborn protein and aluminium combos like real pros.
acid alchemy.
Try these tried-and-tested methods to banish those yellow marks for good:
1. hydrogen peroxide.
This one is for white clothing only.
Pop on some gloves and mix equal parts water and hydrogen peroxide.
Soak the stain in the solution for 30 mins to 1 hour.
Rinse your clothing and wash as normal with smol laundry capsules.
N.B. although hydrogen peroxide is a stronger chemical - especially when undiluted. As soon as it’s mixed with water it is safe to use. As a chemical it occurs naturally (even in our bodies!) and it completely biodegrades very quickly in the environment, breaking down into water and oxygen and it does not bioaccumulate.
2. bicarbonate of soda.
Mix 3 parts bicarbonate of soda to 1 part water into a paste.
Scrub the paste into the stain with an old toothbrush.
For extra oomph, toss in some hydrogen peroxide BUT ONLY if the fabric’s white.
Rinse your clothing and wash as normal with smol laundry capsules.
3. white vinegar.
Mix 2 tbsp vinegar with 1 cup water.
Soak the stained area in the solution for 30 mins to 1 hour.
Rinse your clothing and wash as normal with smol laundry capsules.
4. lemon juice.
Mix equal parts lemon juice and water.
Scrub the solution into the stained area and leave for 1 hour.
Rinse your clothing and wash as normal with smol laundry capsules.
pro tips for best results.
- The most successful stain removals always happen when you act fast! As soon as you see a deodorant or sweat stain building..take action.
- Treat stains BEFORE you wash your clothes… heat can set them for life.
- Be gentle with delicate fabrics - always patch-test acids.
- smol bio laundry capsules contain a BRAND NEW enzyme specifically designed to beat sweat and body grime stains. You won’t find a better boost for beating yellow stains on cuffs, collars and underarms!
- Gloves are your best friend when handling hydrogen peroxide - your hands deserve protection too.
So there we have it. No more sweaty drama. With these tricks, your favourite clothes stay stain-free and ready for action. Happy stain-fighting!