Our hydrogen peroxide method can work to remove dried blood, but it’s more effective on fresh blood stains. However, definitely try removing dried blood stains with hydrogen peroxide using these steps:
Turn the sheets inside out. Run cold water onto the stain, pushing it out from the back of the fabric.
Soak the sheets in cold water for about an hour to dissolve as much of the stain as possible.
Soak a cloth in hydrogen peroxide. Gently rub it into the back of the stain. Continue until the stain is gone.
If the stain is still there, treat the back of the stain with a mild laundry detergent. Use a soft toothbrush to work the detergent into the fibers.
Rinse the stain with cold water.
Repeat if necessary.
Wash as normal.
Don’t dry the garment with heat unless the stain is completely gone.
Some dried blood stains will be impossible to remove. Unfortunately, it might just be time for some new sheets.