Sparky I never thought of ammonia. I used to love the Spay and Wash stick but that is no longer in production. I will look for Shout in an aerosol can. I think that deodorant leaves a grease based stain so ammonia may just do the trick. Thank you for the suggestion.

Ammonia and hot water. Works great..or add STPP.

Does your deodorant contain aluminum? If so, try aluminum free and that may help prevent future stains.

Mamapinky, I forgot about ammonia even though I have read about it here in recent threads. I'm going to buy some today.

Sparky, yes the many deodorants I have tried contains aluminum. I thought to be an anti-perspirant it had to contain aluminum. I have used all major brands. I tried the natural "safe" deodorant but found them completely ineffective. I wonder if the aerosol types would be better?

So interesting, I used to get the worst stains and don't get any anymore...I just checked my deodorant and it does contain aluminum (yuk! What have I been thinking?) I don't know either what caused the stains or why they no longer happen. I don't use ammonia. I wonder if it was something I ate that made the sweat stain...?

There's a lot of stuff in sweat..a lot..a diet high in iron can cause sweat stains...try this experiment..only works on a clean stain free shirt..after removing it if its not going directly into the washer..put it in a bucket with cool water and a bit of detergent. .let it soak till wash day...LOL..lets remember if these shirts are machine dried with underarm stains they will most likely never be removed. Some people have good results with spraying white vinegar on the stains a few minutes before washing, hasn't worked in this house. IMO if its white or very light I'd wash in hot water with ammonia and a powder whites detergent, add STPP if you have it. Water should be as hot as garment can tolorate.

@hmorton - Spray 'n Wash Stain Stick is still around. It's not round but more like a stick deodorant shape. The package is red with a green label. I bought mine recently at Walmart.

I regularly spray vinager on the underarms of our shirts, just to keep them smelling fresh and not like sweat...gross. I keep a spray bottle of the stuff above my washer.

I tried several things, but never had luck. I used undershirts to provide a barrier to my better shirts

I switched to non-antiperspirant deodorant for this reason..well this and alzheimers in the family. I think I actually sweat LESS after giving them up. I swear that stuff build up in your pores just like it does shirts.

If i ever went back, I would use the certain-dri liquids that you use every other day or so, then use deodorant for odor

Jase- thank you I found and bought the Spray and Wash stick that has the name Resolve on the front. Hope that is the correct one.

All, I used some unknown brand of stain stick (no label). I'm betting it was Spray and Wash since it was almost used up and deep in the back of the laundry closet and voila, no stains. I used it on both sides of the fabric added a lot of boiling water (2 gallons) to the machine, Oxi Clean and All Free with Whitener and let it soak for 3 hours. I then ran the wash cycle three times without changing the water for a total wash time of 39 minutes (Yep you read right my machine only has a 13 minute wash cycle). When I took it out, hung to dry and no more stains.

I live in NYC and it is HOT, over 90 with high humidity the past week or so and anti-perspirant with anything (including aluminum) that works is absolutely mandatory, especially on the subway. In the winter I can get away with something less strong.

Thank you for the suggestions. I love how everyone is so helpful. I love the challenge of saving a garment and all of you are so kind and generous with your knowledge. I hate clothes that look like I don't care.

I forgot the buy the ammonia today but will pick some up tomorrow. I am forever spilling something on myself and want to have a little of everything to attack stains.

Clorox 2 powder is the best I've found to prevent build up. I got away from using it and my dress shirts were a mess in a couple of months. I ended up donating them to Goodwill. Since I don't wear undershirts keeping the buildup at bay is a must.