How do I remove bloodstains from polyester?

Have you put the garment in the dryer? If so, you have set the stain. Here are some things to try.

https://www.realsimple.com/home-organizing/cleaning/cleaning-stain-removal/remove-blood-stains

https://m.wikihow.com/Remove-Dried-Blood-Stains-from-Fabric

https://www.cleanipedia.com/gb/laundry/removing-blood-stains-from-clothes.html

I am hoping you used cold water....hot water will set the blood stain. Try again with cold water and soap.

Hello, I would suggest trying to remove the blood with peroxide first prior to washing.

Mix peroxide and blue dawn dishwashing liquid, gently scrub the stain with an old toothbrush. let it sit for awhile and then rinse. do it again if necessary. However, if you used hot water or dried the garment in the dryer, it probably won't come out.

Try soaking the area in milk

Soak the garment in cold water. It always works for me

Thanks

Peroxide works like a charm, then wash in cold water