How to Remove Sweat Stains From a Cotton or Linen Dress

A favourite white cotton dress with yellow marks under the arms is one of the most common reasons good clothes get thrown away. You can remove sweat stains from most cotton and linen dresses at home with cheap ingredients, as long as you treat them the right way and stop doing the one thing that sets them deeper. This guide explains what those stains actually are, the method that works, and how to stop them coming back every summer.

I have rescued dozens of dresses this way, including a 1970s cheesecloth sundress that looked ready for the rag bag. The process takes a little patience, usually an hour of soaking plus a normal wash, but very little effort.

What sweat stains really are

Sweat on its own is mostly water and salt, and it rarely stains. The yellow marks come from a reaction between the proteins and oils in sweat and the aluminium compounds in antiperspirant. Over repeated wears, that mix builds up in the fibres and oxidises, turning yellow on light fabrics and leaving a stiff, waxy patch.

On dark dresses, the same build-up shows as white, chalky marks. That is mostly deodorant residue, and it is much easier to shift.

Knowing this matters because the fix is about breaking down protein and dissolving residue, not bleaching colour out.

How to remove sweat stains from a cotton or linen dress

This method works on white and pale coloured cotton, linen, cotton voile and cotton blends. Always test on an inside seam first.

1. Check the care label. If the dress says dry clean only, or it is silk, wool or viscose, skip to the section on delicate fabrics below.
2. Rinse the area in cool water. Never hot. Heat cooks the proteins into the fibres, which is why stains that went through a hot wash or tumble dryer are the hardest to move.
3. Make a paste. Mix 2 tablespoons of baking soda with 1 tablespoon of water and a few drops of plain washing up liquid. The washing up liquid cuts the oils, the baking soda gently lifts residue.
4. Work it in. Spread the paste over the stain on both sides of the fabric and rub gently with your fingers or a soft toothbrush for about a minute.
5. Leave it for 30 to 60 minutes. Do not let it dry out completely. If it starts to crust, mist it with water.
6. Soak if the stain is old. For yellowing that has built up over a season, dissolve one scoop of oxygen bleach powder, around 2 tablespoons, in 4 litres of warm water at about 40 degrees. Submerge the dress and leave it for 1 to 6 hours.
7. Wash normally. Use the coolest effective cycle on the label, usually 30 or 40 degrees, with your normal detergent.
8. Air dry and check. Look at the stain in daylight before you iron or tumble dry. If any mark remains, repeat the treatment. Heat at this stage will make it permanent.

Most moderate stains lift in one round. Very old yellowing can take two or three.

Why I do not recommend chlorine bleach

The usual advice for yellow stains on white clothes is chlorine bleach. It seems logical: yellow on white, so whiten it. But chlorine bleach often makes sweat stains worse.

It reacts with the proteins in sweat and can deepen the yellow into a stubborn brownish tinge that nothing removes. It also weakens cotton and linen fibres, so the underarm area can thin and tear long before the rest of the dress wears out. On a dress you hope to keep for years, that is a bad trade.

Oxygen bleach, sold as sodium percarbonate or a laundry booster, is gentler on fibres, safe on most colours and works on the organic part of the stain. It is slower, but it does not damage the dress. Linen in particular rewards gentle handling, which we cover in more depth in how to care for a linen dress so it lasts for years.

White marks on dark dresses

White deodorant marks on navy, black or deep coloured dresses usually come out with less fuss. Try these in order:

• Rub the fabric against itself, using a clean part of the same dress. This lifts fresh deodorant powder in seconds.
• Dab with a damp microfibre cloth or a clean nylon stocking.
• For built-up marks, soak the underarms for 30 minutes in 1 part white vinegar to 4 parts cool water, then wash. Vinegar dissolves aluminium residue without fading most dyes.

Avoid baking soda paste on very dark cotton if it is left too long. It can leave a faint pale halo on some dyes.

Delicate fabrics need a gentler hand

Silk, wool, viscose and rayon cannot take long soaks or scrubbing. For these:

Viscose is weak when wet and can shrink or distort, so handle it carefully. Our guide to washing a viscose dress covers this in full. For very old stains on a precious silk dress, a good dry cleaner with stain experience is the safer option.

How to stop sweat stains coming back

Removing a stain is satisfying, but prevention saves the fabric. These habits make the biggest difference:

• Let deodorant dry fully before you put the dress on. Two or three minutes is enough.
• Use less antiperspirant. Most people apply two or three times what they need.
• Consider an aluminium-free deodorant for pale dresses. It does not stop sweat, but it removes the main ingredient behind yellowing.
• Wash after each wear in hot weather. Sweat left in fabric for days sets much harder than sweat washed out the same evening.
• Rinse the underarms before storing any summer dress at the end of the season. Invisible sweat oxidises in storage and appears as yellow marks by next spring. The same logic applies to silk, which we explain in how to store silk dresses so they keep their shape.

Underarm shields, thin washable pads that clip or stick inside a dress, are also worth considering for silk and vintage pieces you wear to weddings or long events.

Frequently asked questions

Can old sweat stains be removed?

Yes, many old sweat stains can be removed with a long soak in oxygen bleach and warm water, sometimes over several rounds. Stains that have been through a hot dryer or ironed are harder and may only fade. Always air dry between attempts so you do not set them further.

Does vinegar remove yellow sweat stains?

Vinegar helps with white deodorant build-up and can soften mild yellowing, but it is rarely enough on its own for set-in yellow stains. A baking soda paste followed by an oxygen bleach soak is more reliable. Do not combine vinegar and baking soda at the same time, as they cancel each other out.

Why do my white dresses turn yellow under the arms?

The yellow comes from sweat proteins and oils reacting with aluminium in antiperspirant, then oxidising in the fabric over time. Hot washes and tumble drying lock it in. Washing promptly in cool water and using less antiperspirant slows the build-up.