How to remove sweat stains and yellowing from shirts
About 7 minutes to read. Published . By the House & Hedge team.
Sweat leaves two kinds of mark on a shirt. One is the stiff, yellowish patch under the arms of a white or light shirt, where sweat, skin oils and deodorant or antiperspirant have gone into the fabric and stayed there. The other is a change of color: a faded or darkened patch on a dyed shirt. Both are easier to treat when they are new, and both are made worse by one common mistake, which is heat. This guide covers how to pretreat, what to wash with, how to deal with a color change, and what to avoid. It draws on two extension services, Kansas State University and the University of Georgia. They overlap on most points, and where they differ the guide says so.
The two sources give treatments and not causes of the yellowing, so this guide does not explain why white fabric turns yellow beyond what they say.
Before you start
Read the care label. The methods below are for washable shirts. UGA Cooperative Extension says to follow the care label, and that its methods apply only to washable items and not to garments labeled dry clean only. For a dry clean only shirt, take it to the cleaner and point out the marks.
Test every product first. UGA’s rule is to always pretest each cleaning agent on an inconspicuous area first, to see whether it changes the color. The inside of a hem or the underside of a cuff will do.
Use one product at a time. Do not layer cleaners on the same spot. If you use bleach of any kind, never combine it with vinegar, ammonia or another cleaning product; the reasons are in what never to mix when cleaning.
Keep heat away until it is gone. UGA says never to iron or apply heat to a material with a deodorant stain, because the combination of chemicals and heat will ruin most fabrics. A dryer is heat. Air dry the shirt after each treatment, look at it in good light, and only machine dry it when the stain has gone. That is a reading of the rule, and a safe one.
Step one: pretreat
Treat the stain before the wash, on the dry shirt, as soon as you see it. Kansas State University Extension’s entries are the clearest set of options.
- Sweat (perspiration). Use a prewash stain remover, or rub with bar soap. Then launder in the hottest water that is safe for the fabric.
- A light deodorant or antiperspirant mark. Pretreat with liquid laundry detergent, then launder.
- A heavy deodorant or antiperspirant mark. Pretreat with a prewash stain remover. Let it stand for 5 to 10 minutes. Then launder using an oxygen bleach.
UGA Cooperative Extension has a different first step for deodorant. It says to rub in undiluted hand dishwashing liquid and then launder. If the stain remains, it lists chlorine bleach, sodium perborate bleach or hydrogen peroxide as next options. As an alternative it describes sponging the back of the stain with a commercial cleaner, then rubbing in full-strength dishwashing liquid, rinsing, and repeating until the stain is gone.
The sources order the stronger options differently, so choose by fabric. Kansas State recommends oxygen bleach. UGA lists chlorine bleach first among its stronger options for apparel. The care label decides, and chlorine bleach belongs only on fabrics whose label allows it. Check, and test.
The only time either source gives for leaving a pretreatment on is the 5 to 10 minutes. Neither describes a long soak, so this guide does not either.
Step two: wash
Wash the shirt in the hottest water that is safe for the fabric, which is the care label’s limit. Kansas State University Extension gives the ranges:
- Hot: 120 to 140 degrees Fahrenheit.
- Warm: 85 to 105 degrees.
- Cold: 65 to 75 degrees.
It adds that water below 60 degrees is too cold for detergents to work. For a stain you cannot identify, it says never to use hot water. A sweat stain you can identify is the first kind, so the hot advice applies if the label allows.
For a stubborn mark, Kansas State suggests washing in a product that contains enzymes or oxygen bleach, in the hottest water safe for the fabric.
Do not put the shirt in the dryer when the wash ends. Check the stained area in daylight while the shirt is wet, then air dry it. If the mark is still there, repeat the pretreatment and the wash. UGA’s own advice is to repeat the treatment until the stain is gone.
The routine in order
- Read the care label, and test your chosen product on a hidden spot.
- Pretreat the dry stain: bar soap or a prewash stain remover for sweat, liquid detergent for a light deodorant mark, and for a heavy one a prewash stain remover left for 5 to 10 minutes.
- Launder in the hottest water the label allows, adding an oxygen bleach for a heavy mark.
- Check the stain while the shirt is wet, in daylight.
- If it remains, repeat. If the color has changed, treat that with ammonia or white vinegar and rinse.
- Air dry until you are sure the stain has gone, then dry as usual.
If the color has changed
Sweat and deodorant can leave a dyed shirt a different color in the stained patch, as well as a stain. UGA Cooperative Extension says that aluminum chloride and similar ingredients in these products are acidic and can alter some dyes. The two sources agree on the remedy:
- A new mark: apply a few drops of ammonia.
- An old mark: apply a few drops of white vinegar.
- Then rinse.
Use these only on the color change, one at a time, and test first. UGA warns that ammonia damages silk and wool, and says that if you must use it on them you should dilute it with an equal amount of water and use it sparingly. For a wool shirt, read the guide on washing wool without shrinking it. Ammonia should be used in a ventilated space, and never alongside bleach.
What to avoid
- Heat before the stain is out. No iron, and no dryer.
- Hot water on a stain you cannot identify. Kansas State says never to use it.
- Solvent-based removers. UGA says products containing hydrocarbons such as xylene or naphtha are highly toxic and often flammable. If you do use one, work in a ventilated area and wear rubber gloves.
- Mixed chemicals. One product at a time, and bleach alone.
- Skipping the test. A stain remover that bleaches the shirt is worse than the stain.
Keeping the next shirt clean
The sources give treatments and not prevention, so these are practical habits and not claims from them. Treat a shirt soon after wearing, before the marks have had time to set. Wash it rather than hanging it back in the closet with the sweat in it. Rotate shirts so that each one gets a rest. A pretreatment on the underarm of a white shirt costs a minute and is far easier than removing a mark that has built up over a season.
When it will not come out
If you have repeated the pretreatment and wash two or three times with no change, and the mark has been through the dryer at some point, it may be set. At that point the choices are to live with it, to wear the shirt under a jacket, or to take it to a dry cleaner and tell them what the mark is. Do not keep escalating with stronger chemicals on a shirt whose fabric the test spot has already shown to be sensitive.
Shirts that smell after washing, rather than stain, are a different problem. The guide to musty towels and laundry covers the detergent build-up and dirty machine that cause it, and the one on cleaning the washing machine covers the rest.
